Glossary
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The ability of a material to withstand surface wear due to rubbing against another surface.
A circuit or register device in a computer that receives, totals and stores numbers.
Precision in the measurement of quantities and in the statement of physical characteristics. Accuracy is expressed in terms of error as a percentage of the specified value (e.g., 10 volts ± 1%), as a percentage of a range (e.g., 2% of full scale), or as parts (e.g., 100 parts per million).
class of measuring instruments or measuring systems that meet stated metrological requirements that are intended to keep measurement errors or instrumental measurement uncertainties within specified limits under specified
operating conditions
Conversion of continuously varying (analog) voltage levels to discrete binary-numbered (digital) values (e.g., a load cell output can be fed through an A/D convertor to produce a continuous stream of digitized information and sent to a digital indicator).
The measure of the bond between a coating and a substrate.
Adhesion is the molecular attraction exerted between bodies in contact.
Defined by Adhesive stress. A = F/S where F is the force perpendicular to the bond and S is the surface area of the bond.
set of operations carried out on a measuring system so that it provides prescribed indications corresponding to given values of a quantity to be measured
The conditions (humidity, pressure, temperature, etc.) of the medium surrounding the load cell.
A polymer with an irregular molecular chain and no crystallinity.
Unit of electrical current intensity. One ampere of current is 6.24 x 1018 electrons passing a point in one second; often shortened to amp.
Anything that corresponds, point for point or value for value, to an otherwise unrelated quantity; data represented by continuous values rather than in discrete steps.
Anything that corresponds, point for point or value for value, to an otherwise unrelated quantity; data represented by continuous values rather than in discrete steps.
(Off Center) A load applied eccentric with the primary axis at the point of application and at some angle with respect to the primary axis.
The total range (in percentage) of full scale capacity over which a digital weight indicator “Automatic Zero Maintenance” (AZM) and “Push-button Auto Zero” (PAZ) functions will operate; Handbook 44.
Used for material that are too flexible for a standard bending test. The sample is supported on a cantilever beam and deflected by a set angle. Deflection, angle and specimen dimensions are used for calculations.
Calculated by 4Q/p R3 where Q is the volumetric flow rate (m3/s) and R is the radius (m) of the capillary.
The viscosity of a fluid, measured at a given shear rate at a fixed temperature.
Acceptable to the authority having jurisdiction over the area for in which a system or equipment will be used.
Pronounced “askee”. A seven-bit plus parity code established by the American National Standards Institute (ANSI) to achieve compatibility between data services.
Apparatus in which the circuits are not necessarily intrinsically safe themselves, but may affect the energy in the intrinsically safe circuits and are relied upon to maintain intrinsic safety.
Data transmission in which time intervals between transmitted characters may be of unequal length. Transmission is controlled by start bits at the beginning of each character and stop bits at the end of each character.
Where public safety is primary, the “Authority Having Jurisdiction” may be a federal, state, local or other regional institution, department or individual. Some examples are a fire chief, fire marshal, chief of a fire protection bureau, labor.
The minimum temperature required for a substance to initiate or cause self-sustained combustion independently of the heating or heated equipment. Also referred to as ignition temperature.
The unit turns off after a preset time if no active weighing is occurring.
On a counting scale, the amount of weight divided by the number of samples which comprised that weight. APW is used by the counting scale to count pieces during normal operation.
A load applied along a line concentric with the primary axis.
Strain in the direction in which the force is applied, ie; on the same axis.
An electronic means of providing “true zero” at all times on a digital scale. AZM compensates for such conditions as indicator or load cell drift or debris on a scale platform by electronically tracking out minor variations around zero.
quantity in a conventionally chosen subset of a given system of quantities, where no subset quantity can be expressed in terms of the others
measurement unit that is adopted by convention for a base quantity
EXAMPLE: In the SI, the meter is the base unit of length. In the CGS systems, the centimeter is the base unit of length. Rainfall, when defined as areic volume (volume per area), has the meter as a coherent derived unit in the SI.
A unit of communications processing speed in digital data communications systems. The speed in baud is the number of discrete conditions of signal events per second. If each signal event represents only one bit condition, baud rate equals bits per second (BPS).
A data coding system in which four binary bits represent the decimal numbers 0 through 9. The BCD equivalent of the decimal number 187 is 0001 1000 0111.
The indicating device of a lever scale.
The modulus of elasticity applicable to the bending of a sample; defined as Stress / Strain.
Force per cm² acting on point on the sample length when a force is applied at that point.
A sample is supported at both ends and a compressive force is applied to the middle of the sample.
A holder designed to receive and position the edges of a lens, meter, window or display.
Data flow in either direction on a wire between pieces of equipment. Each equipment item can both receive and transmit data.
International Bureau of Weights and Measures
The smallest unit of information in a binary system, consisting of a “0” or a “1” (formed from Binary Digit).
A sudden loss of AC line power usually as a result of an overload or other power failure.
indication obtained from a phenomenon, body, or substance similar to the one under investigation, but for which a quantity of interest is supposed not to be present, or is not contributing to the indication
A combination of two or more polymer chains having different features, that are not bonded to each other.
National Conference on Weights and Measures body of officials that sets NTEP policy and has final say in disputes.
A measure of the stress required to separate a layer of material from the base to which it is bonded.
Used to define the parameter that determines if a sample has broken. Two categories of sharp break, where the force drops quickly or a gradual break where the force reduces gradually.
Force at which a break is defined.
Load at which a break is defined.
Force at which a break is defined divided by sample width.
A network of four “leg” components connected so that the input signal may be applied across two branches in parallel and the output signal taken between two points, one on each side of the parallel branches. At some ratio of the resultant four arms of the circuit, the output points are at the same potential, and the output voltage is zero. The bridge then is said to be balanced or set to null.
A material which has a tendency to fracture without appreciable deformation.
A deliberate lowering of line voltage by a power company to reduce load demands.
The ability of a material to resist rupture by pressure, sample dimensions and probe dimensions are required.
The comparison of load cell outputs against standard test loads. Operation that, under specified conditions, in a first
step, establishes a relation between the quantity values with measurement uncertainties provided by measurement standards and corresponding indications with associated measurement uncertainties and, in a second step, uses this information to establish a relation for obtaining a measurement result from an indication
A record (graph) of the comparison of load cell outputs against standard test loads.
expression of the relation between indication and corresponding measured quantity value
graphical expression of the relation between indication and corresponding measurement result
The difference of what the instrument reads on the display and the items true mass.
sequence of calibrations from a reference to the final measuring system, where the outcome of each calibration depends on the outcome of the previous calibration
measurement standard used in calibration
A beam-type load cell that has a machined-out center. The load sensing elements (strain gauges) are mounted on the inside perimeter of this machined center.
The ability of a component or material to store an electrostatic charge; measured in farads. Because the farad is a very large quantity, capacitance in electronic applications is usually expressed in millionths of a farad (microfarads) or millionths of a millionth of a farad (pico farads).
The amount of weight the scale is capable of weighing accurately.
Measures the time of flow of a measured volume of solution through a capillary tube under the force of gravity is compared with the time taken for the same volume of pure solvent, or of another liquid of known viscosity to flow through the same capillary.
Certification that a device meets all applicable requirements of Handbook 44.
Consultative Committee for Amount of Substance — Metrology in Chemistry
reference material, accompanied by documentation issued by an authoritative body and providing one or more specified property values with associated uncertainties and traceabilities, using valid procedures
EXAMPLE: Human serum with assigned quantity value for the concentration of cholesterol and associated
measurement uncertainty stated in an accompanying certificate, used as a calibrator or measurement trueness
control material.
General Conference on Weights and Measures
A receipt for payment or delivery.
Rods installed to prevent a vessel or other weighing system component from gross tipping or extended travel. They do not interfere with normal travel or expansion.
A scale used to verify predetermined weight within prescribed limits.
A chord of a curve is a geometric line segment whose end points both lie on the curve. A secant or a secant line is the line extension of a chord.
The chord modulus is the slope of the chord drawn between any two specified points on the stress-strain curve.
Classes of scales used in commercial weighing not otherwise specified; grain test scales, retail precious metals and semiprecious gem weighing, animal scales, postal scales, and scales used to determine laundry charges.
Vehicle, axle-load, livestock, railway track scales, crane and hopper (other than grain hopper) scales.
Maximum load designated by the manufacturer that can be placed anywhere on the platform of a vehicle, axle-load or livestock scale using the prescribed test pattern (an area at least 4 feet long and as wide as the scale platform).
Tensile load divided by sample width required to cause separation of an adhesive bond.
Fixture designed to peel bond between sandwich type material usually having one rigid and one flexible surface.
Chip technology characterized by a low power requirement and a high noise immunity. CMOS chips are susceptible to damage by electrostatic discharge (ESD).
Committee on Data for Science and Technology
An alternative term for modulus of elasticity.
The ratio of friction force to normal force once slippage has begun between two objects in contact.
A ratio measure of how much force is required before an inert object, of a given material, at rest on another known substance, can be put into motion.
derived unit that, for a given system of quantities and for a chosen set of base units, is a product of powers of base units with no other proportionality factor than one
EXAMPLES: If the metre, the second, and the mole are base units, the metre per second is the coherent derived unit of velocity when velocity is defined by the quantity equation v = dr/dt, and the mole per cubic metre is the coherent derived unit of amount-of-substance concentration when amount-of substance concentration is defined by the quantity equation c = n/V. The kilometre per hour and the knot, given as examples of derived units in 1.11, are
not coherent derived units in such a system of quantities. The centimetre per second is the coherent derived unit of speed in a CGS system of units but is not a coherent derived unit in the SI.
system of units, based on a given system of quantities, in which the measurement unit for each derived quantity is a coherent derived unit
EXAMPLE: Set of coherent SI units and relations between them.
Measure of force / area of two substances that stick to each other.
Stickiness.
The maximum deviation from the straight line drawn between the original no-load and rated load outputs expressed as a percentage of the rated output and measured on both increasing and decreasing loads.
standard measurement uncertainty that is obtained using the individual standard measurement uncertainties associated with the input quantities in a measurement model
property of a reference material, demonstrated by the closeness of agreement between the relation among the measurement results for a stated quantity in this material, obtained according to two given measurement procedures, and the relation obtained among the measurement results for other specified materials
The utilization of supplementary devices, materials or processes to minimize known sources of error.
The ability to be compressed.
Application of a force to reduce a samples height.
A force applied to a strain gauge that causes the gauge wires to compress and their crosssectional area to increase, thus decreasing the gauge resistance.
Deformation which remains in a sample after has been subjected to and released from a specific compress stress for a definite period of time at a prescribed temperature.
The distance that a sample is compressed.
Extent to which a material deforms under a crushing load.
The measured resistance of a specimen to axial loading when expressed as force per unit area.
The stress at which a material deforms found from the stress / strain curve.
Refers to load cells which have a protective coating applied over the strain gauges, terminal strip, etc., within the gauged cavity. The cavity opening may additionally be covered with side plates to protect against physical damage. These cells are suitable for normal indoor applications; they should not be used in wet or washdown applications.
set of operations necessary to preserve the metrological properties of a measurement standard within stated limits
Transmission of serial output data in which the data is transmitted automatically following each indicator display update; usually used to interface indicators to computers, score boards and other remote devices requiring constant data updating.
A drawing or document provided by the manufacturer of the intrinsically safe or associated apparatus that details the allowed interconnections between the intrinsically safe and associated apparatus.
quantity value attributed by agreement to a quantity for a given purpose
quantity-value scale defined by formal agreement
Conventional stress, as applied to tension and compression tests, is force divided by the original gauge length or height.
ratio of two measurement units for quantities of the same kind
EXAMPLE 1: km/m = 1 000 and thus 1 km = 1 000 m.
EXAMPLE 2: h/s = 3 600 and thus 1 h = 3 600 s.
EXAMPLE 3: (km/h)/(m/s) = (1/3.6) and thus 1 km/h = (1/3.6) m/s.
The ability of an instrument to deliver the same weight reading for a given object on the corners of the weighing pan.
Variations in the weight of an object that is moved to corner positions on the weighing pan.
compensation for an estimated systematic effect
The smallest increment of weight displayed.
number larger than one by which a combined standard measurement uncertainty is multiplied to obtain an expanded measurement uncertainty
interval containing the set of true quantity values of a measurand with a stated probability, based on the information available
probability that the set of true quantity values of a measurand is contained within a specified coverage interval
The computer module or chip that controls fetching, decoding and executing instructions; controls processing operations for the device.
The change in load cell output occurring with time, while under load, and with all environmental conditions and other variables remaining constant; usually measured with Rated Load applied and expressed as a percent of Rated Output over a specific period of time.
Measurement of the distance a sample changes due to creep.
Rate of change of a sample due to creep.
The change in no-load output occurring with time, after removal of a load which has been applied for a specific period of time; usually measured over a specified time period immediately following removal of rated load and expressed as a percent of rated output.
Alternative name for a compression test, usually to fracture or break.
Sample where the molecules are arranged in an irregular order.
Point at which a sample that requires time to cure achieves its maximum strength.
Flow of electrons past a point in a specified period of time; measured in amperes.
A current-based method of serial communications between digital devices; a logic high is represented by current flowing in the loop; a logic “low” is represented by a lack of current flowing in the loop.
Exercising a sample between limits for a duration of fixed number times.
Value of the smallest increment indicated (displayed) by a scale.
A dampening device used to reduce scale oscillations.
measurement error of a measuring instrument or measuring system at a specified measured quantity value
maximum interval through which a value of a quantity being measured can be changed in both directions without producing a detectable change in the corresponding indication
The fixed force of the weigh bridge, platform, and other load-supporting structures of the scale, the value of which is to be permanently balanced or cancelled out in the weight or measuring system.
Determines the location of the decimal point or number of dummy zeros for the graduation size. Example: 8888.88 would have two places to the right of the decimal point, 888880 would have one dummy zero.
component of measurement uncertainty resulting from the finite amount of detail in the definition of a measurand
The change in length along the Primary Axis of the load cell between no-load and Rated Load conditions.
A change in dimensions of a material.
Force required to separate two bonded materials by a peeling action.
Force required to separate two bonded materials by a peeling action divided by the sample width.
Transmission of serial output data which requires a manual “Print” command to initiate the output data. Usually used to interface indicators to printers.
Measurement of yarn size.
Device for measuring the density of plastic at 23 C.
quantity, in a system of quantities, defined in terms of the base quantities of that system
EXAMPLE: In a system of quantities having the base quantities length and mass, mass density is a derived quantity defined as the quotient of mass and volume (length to the third power).
measurement unit for a derived quantity
EXAMPLES: The metre per second, symbol m/s, and the centimetre per second, symbol cm/s, are derived units of speed in the SI. The kilometre per hour, symbol km/h, is a measurement unit of speed outside the SI but accepted for use with the SI. The knot, equal to one nautical mile per hour, is a measurement unit of speed outside the SI.
measured quantity value, obtained by a given measurement procedure
device or substance that indicates the presence of a phenomenon, body, or substance when a threshold value of an associated quantity is exceeded
EXAMPLES: Halogen leak detector, litmus paper.
Die swell is a memory effect in which the polymer tries to return to its former shape after extrusion through a die.
The smallest increment of weight that the indicator resolves.
System of signal representation employing discrete rather than continuously variable (analog) values.
The ability of a digital indicator to smooth bouncy or erratic readings by taking several readings and averaging them together before sending the signal to the display. Increasing the digital averaging slows the indicators update rate.
Is used to stabilize the readout of the indicator. The more digital filtering applied, the more accurate display reading, but a longer settling time is required.
An integrated circuit contained within a standard housing characterized by its low profile, rectangular body, and symmetrical placement of leads along two opposing sides the device.
largest change in a value of a quantity being measured that causes no detectable change in the corresponding indication
Determines if the count by will be 1, 2, or 5.
indicating measuring instrument where the output signal is presented in visual form
Determines the amount of increments a scale offers.
A built-in scale having a self-contained under structure.
A method of printing in which a rectangular array (matrix) of spaces are filled in to form alphanumeric and punctuation characters.
The effect of thinning of a extruded polymer when it leaves the die caused by the effect of gravity on the extruded polymer after the die.
In filling operations, the weight value over which material is slowly handled to provide a more accurate cutoff.
A continuously upward or downward change in the number displayed on the digital readout. This could be due to temperature, static electricity or RFI (radio frequency interference).
A temporary loss of electrical power normally caused by utility and maintenance switching functions where break-before-make switching strategies are used.
Can be easily formed or shaped (opposite of brittle).
The ability of a material to deform plastically without fracturing.
Preformed sample specimen for tensile testing, enabling the sample to be gripped easily and have a section of the sample formed to high tolerance dimensions.
Resistance to relative movement of two bodies that are already in motion.
The minimum scale division or value for which a device complies with applicable requirements, e.g., bench or counter scale.
Value of a verification scale division specified by the manufacturer; sets value for tolerances and accuracy class.
Any load applied parallel to, but not concentric with, the Primary Axis.
In determining the edge tear resistance of a paper sample, a strip of paper is simultaneously torn at opposite edges of the strip by means of a thin, V-notch beam held in a stirrup. A tearing force is applied at a constant rate of elongation until the paper begins to tear.
A data storage component whose data can be repeatedly read out; the stored data can be erased by an electrical signal and new data then can be programmed into the component.
The point beyond which the deformation of a structure or material are no longer purely elastic.
The ratio of stress, within the proportional limit, to the corresponding strain.
The force at the elastic limit dived by sample width.
Tendency of a material to return to its original shape after it has been stretched or compressed.
Extraneous undesirable currents or voltages which interfere with desirable electrical quantities. Some causes are distant lightning, radio transmitters, welding equipment, electrical switching equipment, poor brush contact on motors, and other electronic devices utilizing switching power supplies.
A negatively-charged subatomic particle that orbits the nucleus of an atom. Electrical current is the flow of electrons.
An electric charge on the surface of an insulated object.
Extension of a specimen which has been stretched in a test. The percentage elongation is an indication of ductility.
Extension of a specimen reported at break.
The extension of a specimen reported at the yield point.
Interference caused by electrical fields due to capacitive coupling, or magnetic fields due to mutual inductance of electromagnetic fields (radio waves).
Work required or work done during a test. The area under a force curve divided by the change in extension.
Force divided by the original sample area.
Refers to load cells which have a strain gauge cavity filled with a potting compound. The cavity opening is also generally protected with loose-fitting side plates or molded plastic to protect against physical damage. These cells are protected from normal environmental factors in indoor or outdoor applications. They should not be submersed or washed down.
A data storage component whose data can be repeatedly read out; the stored data can be erased by applying ultraviolet light, and new data then can be programmed into the component.
The algebraic difference between the indicated and true value of the load being measured.
A rapid discharge of an electrostatic potential that can cause damage to integrated circuits.
Points placed on a graph which may be used to report load, stress, strain, time or extension.
The voltage or current applied to the input terminals of the load cell.
Method of matching load cell outputs in a multicell system by adjusting the excitation voltage to each individual load cell. Adjustment is made by changing the setting of a variable resistor in series with the excitation input.
product of a combined standard measurement uncertainty and a factor larger than the number one
An enclosure that is capable of withstanding an explosion of a specified gas or vapor which may occur within it and of preventing the ignition of the gas surrounding the enclosure. The enclosure also must operate at such an external temperature so that it is incapable of igniting its surrounding atmosphere.
Measurement of movement of the testing machine.
Ability to tear out an extension before the main test starts.
Device to measure accurately the movement of a sample either by contacting directly on the sample or a non-contacting optical method.
Removal of one component from another as in “Insertion / Extraction” test.
All products displaying this symbol have been approved for use in hazardous (classified) locations when following the proper installation procedures and drawings, and utilizing intrinsic safety barriers.
Device for measuring the force required to break a thin film material by puncturing. Uses free falling masses.
Fatigue is a process by which a material is weakened by cyclic loading.
Effects of fatigue on a sample experienced over time.
Point at which a sample fractures or reaches a defined point during cycling.
A passive electric component used to suppress high frequency noise in electronic circuits. Also called ferrite blocks, ferrite beads, ferrite rings, ferrite EMI filters, or a ferrite choke.
Specifies the number of consecutive readings that must fall outside the filter threshold setting before filtering is suspended. If set to none digital filtering is always enabled.
Specifies the filter threshold in display divisions. When a specified number of consecutive readings fall outside the threshold filtering is suspended. This helps settling times when high filtering rates are used.
Strength of an adhesive bond between two materials determined by a flexing motion.
The ratio, within the elastic limit, of the applied stress on a test specimen in flexure to the corresponding strain.
Flexural resistance is a measurement of a material and corresponds to the maximum stress per unit area that a specimen can withstand without breaking when subjected to a bending force.
Measurement of force required to permanently deform a sample by bending.
Maximum stress developed in a specimen just before it cracks or breaks in a flexure test.
A bending test.
Thin steel or plastic bands or plates which replace the pivots and bearings of a conventional scale, allowing less movement and reducing friction.
Term used to describe polymers that have a Melt Index of less than 1.
Food testing, a load peak or fall in the first compression cycle (bite) indicating the sample has crumbled or fractured but has not completely broken.
A break in the sample.
Direction applied to a crack to open it. Open, forward or transverse shear.
Test ending in a sample fracture, user defined.
A pivot point for a lever.
Simultaneous, two-way, independent data transmission in both directions.
A power supply that allows conduction only when signal magnitude is within specified limits.
Unit of length which is used to calculate strain, the original sample length, height or grip separation.
Test to BS757.
Change in an amorphous polymer from viscous to hard and relatively brittle.
Specifies the number of full scale graduations. Capacity = Grads X Count By.
A mark on an instrument or vessel indicating degrees or quantity.
Term used to describe the strength of a polyurethane or rubber compound in the early stages of cure.
Guide to the Expression of Uncertainty in Measurement
The property of cohesiveness and stickiness.
Data transmission in both directions, but not simultaneously. See “full duplex”.
A comprehensive set of requirements for weighing and measuring devices that are used in commerce and law enforcement activities; not a federal law, but developed and updated annually by the National Conference on Weights and Measures. Its complete title is “Specifications, Tolerances, and Other Technical Requirements for Weighing and Measuring Devices”.
Exchange of predetermined signals between two devices for purpose of control.
Resistance to permanent deformation.
A location where fire or explosion hazards may exist due to the presence of flammable gases or vapors, flammable liquids, combustible dust or easily-ignitable fibers or flyings.
Refers to load cells which have a metallic protective cover welded or soldered in place to protect the strain gauge cavity. Some cells of this type have additional protection at the cable entry such as a glass-to-metal seal. These load cells provide the best possible protection in harsh chemical or washdown environments.
A filter passing frequency components above a designated frequency and rejecting components below that frequency.
The amount by which a material body is deformed (the strain) is linearly related to the force causing the deformation (the stress).
The mechanical energy loss that always occurs under loading and unloading, proportional to the area between the loading and unloading load-deflection curves within the elastic range.
The maximum difference between load cell output readings for the same applied load. One reading is obtained by increasing the load from zero and the other reading is obtained by decreasing the load from rated load. Measurements should be taken as rapidly as possible to minimize creep.
Obtaining different readings for the same object.
International Atomic Energy Agency
International Council for Science
International Electrotechnical Commission
International Federation of Clinical Chemistry and Laboratory Medicine
International Laboratory Accreditation Cooperation
The striking of one body against another.
The energy dissipated during an impact.
The force / sample dimension in an impact test.
measuring instrument providing an output signal carrying information about the value of the quantity being measured
EXAMPLES: Voltmeter, micrometer, thermometer, electronic balance.
quantity value provided by a measuring instrument or a measuring system
set of quantity values bounded by extreme possible indications
Environmental elements that may alter or interrupt an electronic or mechanical indication (e.g., temperature, humidity, radio frequency interference, barometric pressure, electric power).
quantity that, in a direct measurement, does not affect the quantity that is actually measured, but affects the relation between the indication and the measurement result
EXAMPLE 1: Frequency in the direct measurement with an ammeter of the constant amplitude of an alternating
current.
EXAMPLE 2: Amount-of-substance concentration of bilirubin in a direct measurement of haemoglobin amount of-
substance concentration in human blood plasma.
EXAMPLE 3: Temperature of a micrometer used for measuring the length of a rod, but not the temperature of the rod itself which can enter into the definition of the measurand.
EXAMPLE 4: Background pressure in the ion source of a mass spectrometer during a measurement of amount of-
substance fraction.
quantity that must be measured, or a quantity, the value of which can be otherwise obtained, in order to calculate a measured quantity value of a measurand
EXAMPLE: When the length of a steel rod at a specified temperature is the measurand, the actual temperature, the length at that actual temperature, and the linear thermal expansion coefficient of the rod are input quantities in a measurement model.
Pushing or forcing one body in to another, as in insertion / extraction test.
The displayed number continues to vary randomly instead of progressively. See “drift”.
average of replicate indications minus a reference quantity value
continuous or incremental change over time in indication, due to changes in metrological properties of a measuring instrument
component of measurement uncertainty arising from a measuring instrument or measuring system in use
The DC resistance measured between the load cell circuit and the load cell structure; normally measured at fifty volts DC and under standard test conditions.
A device or circuit that allows two units to communicate. Some of the standard interfaces used in the scale industry are 20 mA current loop, BCD, RS-232, RS-422 and RS-485.
condition of measurement, out of a set of conditions that includes the same measurement procedure, same location, and replicate measurements on the same or similar objects over an extended period of time, but may include other
conditions involving changes
measurement precision under a set of intermediate precision conditions of measurement
| The smallest increment of the A/D converter. |
measurement standard recognized by signatories to an international agreement and intended to serve worldwide
EXAMPLE 1: The international prototype of the kilogram.
EXAMPLE 2: Chorionic gonadotrophin, World Health Organization (WHO) 4th international standard 1999, 75/589, 650 International Units per ampoule.
EXAMPLE 3: VSMOW2 (Vienna Standard Mean Ocean Water) distributed by the International Atomic Energy
Agency (IAEA) for differential stable isotope amount-of substance ratio measurements
A rating system that defines a products or enclosures protection against the ingress of solid objects and liquids.
system of quantities based on the seven base quantities: length, mass, time, electric current, thermodynamic temperature, amount of substance, and luminous intensity
system of units, based on the International System of Quantities, their names and symbols, including a series of prefixes and their names and symbols, together with rules for their use, adopted by the General Conference on Weights and Measures (CGPM)
The term “interval” is used together with the symbol [a, b] to denote the set of real numbers x for which a ≤ x ≤ b, where a and b a are real numbers. The term “interval” is used here for ‘closed interval’. The symbols a and b denote the ‘end-points’ of the interval [a, b].
measurement standard based on an inherent and reproducible property of a phenomenon or substance
EXAMPLE 1: Triple-point-of-water cell as an intrinsic measurement standard of thermodynamic temperature.
EXAMPLE 2: Intrinsic measurement standard of electric potential difference based on the Josephson effect.
EXAMPLE 3: Intrinsic measurement standard of electric resistance based on the quantum Hall effect.
EXAMPLE 4: Sample of copper as an intrinsic measurement standard of electric conductivity.
A network designed to limit the energy (voltage and current) available to the protected circuit in the hazardous (classified) location under specified fault conditions.
A grounding system that has a dedicated conductor, separate from the power system, so ground currents will not normally flow, and which is reliably connected to a ground electrode in accordance with Article 200 of the NEC.
A measure of the capability of a polymer in solution to enhance the viscosity of the solution.
A circuit in which any spark or thermal effect is incapable of causing ignition of a mixture of flammable or combustible material in air under prescribed test conditions in its most easily ignitable concentration.
An assembly of interconnected intrinsically safe apparatus, associated apparatus and interconnecting cables in which the parts of the system, which may be used in hazardous (classified) locations, are intrinsically safe circuits; may include more than one intrinsically safe circuit.
The circuits or devices that allow a digital unit to send (output) data and receive (input) data.
Consists of the letters IP followed by two digits and an optional letter. As defined in international standard IEC 60529, it classifies the degrees of protection provided against the intrusion of solid objects (including body parts like hands and fingers), dust, accidental contact, and water in electrical enclosures.
International Organization for Standardization
International Organization for Standardization, Reference Materials Committee
International Union of Pure and Applied Chemistry
International Union of Pure and Applied Chemistry — Commission on Isotopic Abundances and Atomic Weights
International Union of Pure and Applied Physics
A box or enclosure used to join different runs of cable or wiring; it contains space and terminals for connecting and branching the enclosed conductors and adjustments to provide load cell trimming.
Joint Committee for Guides in Metrology
Joint Committee for Guides in Metrology, Working Group 1 on the GUM
Joint Committee for Guides in Metrology, Working Group 2 on the VIM
aspect common to mutually comparable quantities
EXAMPLE 1: The quantities diameter, circumference, and wavelength are generally considered to be quantities of the same kind, namely of the kind of quantity called length.
EXAMPLE 2: The quantities heat, kinetic energy, and potential energy are generally considered to be quantities of the same kind, namely of the kind of quantity called energy.
EXAMPLE 3: The quantities moment of force and energy are, by convention, not regarded as being of the same kind, although they have the same dimension. Similarly for heat capacity and entropy, as well as for number of entities, relative permeability, and mass fraction.
Measurement of the degradation of a material when a knot is formed due to compressive and tensile forces.
Shear stress that acts on a overlapped joint.
To maintain a closed (energized) state in a pair of relay contacts after initial energization from a single electrical pulse.
A relay which locks into the mode for which it is energized (On or Off); requires a start-stop button; once activated it stays activated until the setpoint is reached or the stop button is pushed.
A semiconductor light source that emits visible light or invisible infrared radiation.
A tool that transfers force equally with reduction or multiplication.
Shear stress that acts on a overlapped joint.
extreme operating condition that a measuring instrument or measuring system is required to withstand without damage, and without degradation of specified metrological properties, when it is subsequently operated under its rated operating conditions
Mass per unit length.
Section of the stress / strain curve where increase in load is proportional to extension.
Refers to the quality of delivering identical sensitivity throughout the weighing capacity of a scale or balance.
This method minimizes deviation between actual and displayed weights within the scale weighing range. It utilizes three calibration points, one at zero, center span and full span.
This test measures the ability of an instrument to have consistent sensitivity throughout the weighing range.
A thin, flat electronic visual display that uses the light modulating properties of liquid crystals (LCs). LCs do not emit light directly.
The load applied to a scale base that is actually being measured by the weighing system.
The load reported at point at which a specified deviation from proportionality of stress and strain occurs.
A device which produces an output signal proportional to the applied weight or force. Types of load cells include beam, S-beam, platform, compression and tension.
A filter which passes frequency components below a designated frequency and rejecting components above that frequency.
A lower yield is defined as being the first minima to occur after the upper yield.
Force / area reported at a point of lower yield.
Points placed on a graph to report load, extension, stress, strain. May be moved to recalculate values.
The quantity of matter in a body.
measuring instrument reproducing or supplying, in a permanent manner during its use, quantities of one or more given kinds, each with an assigned quantity value
EXAMPLES: Standard weight, volume measure (supplying one or several quantity values, with or without a
quantity-value scale), standard electric resistor, line scale (ruler), gauge block, standard signal generator,
certified reference material.
Change in length / original length and requires the span of the supports and the radius of the bend.
Force per unit area acting at a point along the length of a sample resulting from the bending moment applied at that point.
extreme value of measurement error, with respect to a known reference quantity value, permitted by specifications or regulations for a given measurement, measuring instrument, or measuring system
Algebraic difference between maximum and minimum stress.
quantity intended to be measured
EXAMPLE 1: The potential difference between the terminals of a battery may decrease when using a voltmeter with a significant internal conductance to perform the measurement. The open-circuit potential difference can be calculated from the internal resistances of the battery and the voltmeter.
EXAMPLE 2: The length of a steel rod in equilibrium with the ambient Celsius temperature of 23 °C will be different from the length at the specified temperature of 20 °C, which is the measurand. In this case, a correction is necessary.
quantity value representing a measurement result
closeness of agreement between a measured quantity value and a true quantity value of a measurand
estimate of a systematic measurement error
measured quantity value minus a reference quantity value
function of quantities, the value of which, when calculated using known quantity values for the input quantities in a measurement model, is a measured quantity value of the output quantity in the measurement model
generic description of a logical organization of operations used in a measurement
Measurement methods may be qualified in various ways such as substitution measurement method, differential measurement method or null measurement method
mathematical relation among all quantities known to be involved in a measurement
closeness of agreement between indications or measured quantity values obtained by replicate measurements on the same or similar objects under specified conditions
phenomenon serving as a basis of a measurement
EXAMPLE 1: Thermoelectric effect applied to the measurement of temperature.
EXAMPLE 2: Energy absorption applied to the measurement of amount-of-substance concentration.
EXAMPLE 3: Lowering of the concentration of glucose in blood in a fasting rabbit applied to the measurement of
insulin concentration in a preparation.
detailed description of a measurement according to one or more measurement principles and to a given measurement method, based on a measurement model and including any calculation to obtain a measurement result
measurement precision under a set of repeatability conditions of measurement
measurement precision under reproducibility conditions of measurement
set of quantity values being attributed to a measurand together with any other available relevant information
realization of the definition of a given quantity, with stated quantity value and associated measurement uncertainty, used as a reference
EXAMPLE 1: 1 kg mass measurement standard with an associated standard measurement uncertainty of 3 μg.
EXAMPLE 2: 100 ohm measurement standard resistor with an associated standard measurement uncertainty of 1 μohm.
EXAMPLE 3: Caesium frequency standard with a relative standard measurement uncertainty of 2 10–15.
EXAMPLE 4: Standard buffer solution with a pH of 7.072 with an associated standard measurement uncertainty of 0.006.
EXAMPLE 5: Set of reference solutions of cortisol in human serum having a certified quantity value with
measurement uncertainty for each solution.
EXAMPLE 6: Reference material providing quantity values with measurement uncertainties for the mass
concentration of each of ten different proteins.
closeness of agreement between the average of an infinite number of replicate measured quantity values and a reference quantity value
non-negative parameter characterizing the dispersion of the quantity values being attributed to a measurand, based on the information used
real scalar quantity, defined and adopted by convention, with which any other quantity of the same kind can be compared to express the ratio of the two quantities as a number
series of elements of a measuring system constituting a single path of the signal from a sensor to an output element
EXAMPLE 1: Electro-acoustic measuring chain comprising a microphone, attenuator, filter, amplifier, and voltmeter.
EXAMPLE 2: Mechanical measuring chain comprising a Bourdon tube, system of levers, two gears, and a mechanical dial.
device used for making measurements, alone or in conjunction with one or more supplementary devices
set of values of quantities of the same kind that can be measured by a given measuring instrument or measuring system with specified instrumental measurement uncertainty, under defined conditions
set of one or more measuring instruments and often other devices, including any reagent and supply, assembled and adapted to give information used to generate measured quantity values within specified intervals for quantities of specified kinds
device, used in measurement, that provides an output quantity having a specified relation to the input quantity
EXAMPLES: Thermocouple, electric current transformer, strain gauge, pH electrode, Bourdon tube, bimetallic strip.
A special ohmmeter for measuring resistances in the megohm (106 ohms) range; also called a megger.
Defined as the weight of polymer in grams flowing through an aperture of specific diameter and length, with defined pressure over a 10 minute period. Also know as Melt Index.
A measure of the extensional viscosity of polymer melts.
A measure of the extensional viscosity of polymer melts.
Defined as the volume of polymer in cm³ flowing through an aperture of specific diameter and length, with defined pressure over a 10 minute period.
The temperature at which the structure of a crystalline polymer is destroyed to yield a liquid.
A fixed or variable resistor in which the resistance element is a thin or thick film of a metal alloy deposited on a substrate made of plastic or ceramic material.
comparability of measurement results, for quantities of a given kind, that are metrologically traceable to the same reference
EXAMPLE: Measurement results, for the distances between the Earth and the Moon, and between Paris and London, are metrologically comparable when they are both metrologically traceable to the same measurement
unit, for instance the metre
property of a set of measurement results for a specified measurand, such that the absolute value of the difference of any pair of measured quantity values from two different measurement results is smaller than some chosen multiple of the standard measurement uncertainty of that difference
property of a measurement result whereby the result can be related to a reference through a documented unbroken chain of calibrations, each contributing to the measurement uncertainty
sequence of measurement standards and calibrations that is used to relate a measurement result to a reference
metrological traceability where the reference is the definition of a measurement unit through its practical realization
science of measurement and its application
A prefix meaning millionths; symbol is “m”.
The number of microvolts of live load signal that are needed to change the display.
Minimum dead load is specified for NTEP load cells. In a given application, the dead load applied to each cell must be greater than or equal to the minimum dead load specified by the load cell manufacturer.
Usually used with counting scales. Refers to the piece weight required in counting mode.
The physical measurement of stiffness in a material, equaling the ratio of applied load to the resultant deformation of the material.
The modulus of elasticity applicable to the bending of a beam; defined as Stress / Strain.
Rate of change of strain as a function of stress. The slope of the straight line portion of a stress-strain diagram.
Rate of change of strain as a function of stress in a specimen subjected to shear or torsion loading.
In bending, the modulus of rupture is the bending moment at fracture divided by the section modulus.
Work done on a unit volume of material as a simple tensile force is gradually increased from zero to the value causing rupture is defined as the Modulus of Toughness. This may be calculated as the entire area under the stress-strain curve from the origin to rupture.
Sets the level in display divisions that motion is detected. If motion is not detected for 1 second the standstill annunciator lights. Certain functions like Tare, Zero, and Print are prohibited while the scale is in motion.
A circuit used in an indicator to sense when the displayed weight data is changing at a greater rate than preset limits (or is unstable) and to inhibit certain functions during this time. Functions inhibited may be data output, entry of a push-button auto zero, entry of an auto tare value or activation of zero tracking.
A voltage-dependent resistor whose resistance predictably changes with voltage applied; used in transient protectors as a shunt protection device.
measurement unit obtained by multiplying a given measurement unit by an integer greater than one
EXAMPLE 1: The kilometre is a decimal multiple of the metre.
EXAMPLE 2: The hour is a non-decimal multiple of the second.
The maximum number of scale divisions for which a product has been approved. The nmax must be greater than or equal to the number of divisions for which the scale will be configured.
measurement standard recognized by national authority to serve in a state or economy as the basis for assigning quantity values to other measurement standards for the kind of quantity concerned
An association of state and local officials. Federal and industry representatives that adopt uniform (model) laws and regulations (e.g., NIST Handbook 44).
Reduction of the cross sectional area of the metal in a portion of the sample caused by stretching.
Binary logic in which a high negative state represents a “1” condition and a low negative state represents a “0” state.
After an item is removed from the scale, any tared value will be displayed as a negative number. See “tare”.
National Electrical Manufacturers Association.
A fluid with a constant viscosity at a given temperature regardless of the rate of shear.
An agency of the federal government to which all precision measurements are traceable. Formerly the National Bureau of Standards (NBS).
set of quantity values, bounded by rounded or approximate extreme indications, obtainable with a particular setting of the controls of a measuring instrument or measuring system and used to designate that setting
The designed normal maximum load cell capacity. Output load cell sensitivity is based on this capacity unless otherwise specified.
property of a phenomenon, body, or substance, where the property has no magnitude
EXAMPLE 1: Sex of a human being.
EXAMPLE 2: Colour of a paint sample.
EXAMPLE 3: Colour of a spot test in chemistry.
EXAMPLE 4: ISO two-letter country code.
EXAMPLE 5: Sequence of amino acids in a polypeptide.
rounded or approximate value of a characterizing quantity of a measuring instrument or measuring system that provides guidance for its appropriate use
EXAMPLE 1: 100 ohm as the nominal quantity value marked on a standard resistor.
EXAMPLE 2: 1 000 ml as the nominal quantity value marked on a single-mark volumetric flask.
EXAMPLE 3: 0.1 mol/l as the nominal quantity value for amount-of-substance concentration of a solution of
hydrogen chloride, HCl.
EXAMPLE 4: –20°C as a maximum Celsius temperature for storage.
Stress calculated on the assumption of a uniform cross-sectional area, without defects or deformities taken in to consideration.
Relays that will stay at the logic level based on the current setpoint data. These relays will “toggle” from energized to de-energized states depending on the signal sent to them.
The maximum deviation of the calibration curve from a straight line drawn between the no-load and rated load outputs, expressed as a percentage of the rated output and measured on increasing load only.
Fluids having viscosities that depend on the shear rate.
A computer storage medium whose contents remain unaltered when the power is switched off; contents are available when power is switched on again.
A program of cooperation between the National Conference On Weights & Measures, NIST, state weights and measures officials and the private sector for determining conformance of weighing equipment with the provisions of H-44.
measurement uncertainty where the specified measured quantity value is zero
number in the expression of a quantity value, other than any number serving as the reference
EXAMPLE 1: In an amount-of-substance fraction equal to 3 mmol/mol, the numerical quantity value is 3 and the unit is mmol/mol. The unit mmol/mol is numerically equal to 0.001, but this number 0.001 is not part of the numerical quantity value, which remains 3.
EXAMPLE 2: For a quantity value of 5.7 kg, the numerical quantity value is {m} = (5.7 kg)/kg = 5.7. The same quantity value can be expressed as 5 700 g in which case the numerical quantity value {m} = (5 700 g)/g = 5 700.
mathematical relation between numerical quantity values, based on a given quantity equation and specified measurement units
A manufacturer who produces equipment for use or inclusion by another manufacturer in its product.
measurement unit that does not belong to a given system of units
EXAMPLE 1: The electronvolt is an off-system measurement unit of energy with respect to the SI.
EXAMPLE 2 Day, hour, minute are off-system measurement units of time with respect to the SI.
Point of interception on the stress / strain curve, parallel to the line of best fit offset by a defined extension.
The unit of electrical resistance. The resistance through which a current of one ampere will flow when a voltage of one volt is applied.
The relationship between current, voltage and resistance. Current varies directly with voltage, and inversely with resistance (I = E/R, where I = Current, E = Voltage and R = Resistance).
International Organization of Legal Metrology
Treaty organization that recommends technical requirements for weighing and measuring equipment prior to the sale or distribution of a model or type within the state, nation, etc.
quantity, defined by a conventional measurement procedure, for which a total ordering relation can be established, according to magnitude, with other quantities of the same kind, but for which no algebraic operations among those quantities exist
EXAMPLE 1: Rockwell C hardness.
EXAMPLE 2: Octane number for petroleum fuel.
EXAMPLE 3: Earthquake strength on the Richter scale.
EXAMPLE 4: Subjective level of abdominal pain on a scale from zero to five.
quantity-value scale for ordinal quantities
EXAMPLE 1: Rockwell C hardness scale.
EXAMPLE 2: Scale of octane numbers for petroleum fuel.
The signal (voltage, current, pressure, etc.) produced by a load cell. Where the output is directly proportional to excitation, the signal must be expressed in terms such as Volts per Volt, Millivolts per Volt, or Volts per Ampere, etc., of excitation.
quantity, the measured value of which is calculated using the values of input quantities in a measurement model
The algebraic difference between the Outputs at no-load and at Rated Load.
The maximum load, in percent of Rated Capacity, which can be applied without producing a permanent shift in performance characteristics beyond those specified.
The maximum load, in percent of Rated Capacity, which can be applied without producing a structural failure.
Office of Weights and Measures at NIST.
A circuit in which the components are connected across each other. The voltage applied to each component is the same.
Type of data communication in which all elements in an information item (bits in a word) are acted upon simultaneously, rather than one at a time as in serial communications.
A method of error checking where an extra bit is sent to establish an even or odd number of ones in the data of a character.
Extension of the AZM function of a digital weight indicator through the use of a front panel push-button.
Another name for bond strength.
Force / contact area in a peel test.
Ratio of final gauge against original gauge length.
Ratio of final gauge against original gauge length at fracture or break.
Calculates the extension (as a percentage of sample gauge length / sample height) at the point where a line drawn parallel to the linear portion line, through the point of fracture, intercepts zero load.
Calculates the elongation (as a percentage of sample gauge length / height), at which a line parallel to the linear portion line, drawn from the point of maximum force, intercepts zero load.
Percentage total elongation at maximum force is calculated as being the extension expressed as a percentage of sample gauge-length, at the position where the load readings are highest.
Deformation that remains after the load causing it is removed. It is the permanent part of the deformation beyond the elastic limit of a material.
The properties of a material that allow it to be shaped and to retain its shape.
A moveable weight that counterbalances the load on a scale.
Ratio of lateral strain to axial strain in an axial loaded specimen.
A point at which signals may be introduced to or extracted from a circuit, device, or system.
A variable resistor employed as a voltage divider.
A load cell which is environmentally sealed by filling the strain gauge cavity with a material that protects the gauges from environmental hazards such as moisture. The potting material must not interfere with normal strain gauge movement, and allow the gauges to return to their normal zero output position.
Weight value which is set to allow for material in suspension during a filling operation.
Load applied to a sample before it is tested to remove unwanted sample or fixture movement.
The process of supplying an enclosure with clean air or an inert gas with or without continuous flow at sufficient pressure to prevent the entrance of combustible dust.
The axis along which the load cell is designed to be loaded; normally its geometric center line.
measurement standard established using a primary reference measurement procedure, or created as an artifact, chosen by convention
EXAMPLE 1: Primary measurement standard of amount-of-substance concentration prepared by dissolving a known amount of substance of a chemical component to a known volume of solution.
EXAMPLE 2: Primary measurement standard for pressure based on separate measurements of force and area.
EXAMPLE 3: Primary measurement standard for isotope amount-of-substance ratio measurements, prepared by mixing known amount-of-substances of specified isotopes.
EXAMPLE 4: Triple-point-of-water cell as a primary measurement standard of thermodynamic temperature.
EXAMPLE 5: The international prototype of the kilogram as an artifact, chosen by convention.
reference measurement procedure used to obtain a measurement result without relation to a measurement
standard for a quantity of the same kind
EXAMPLE: The volume of water delivered by a 50 ml pipette at 20 °C is measured by weighing the water delivered by the pipette into a beaker, taking the mass of beaker plus water minus the mass of the initially empty beaker, and correcting the mass difference for the actual water temperature using the volumic mass (mass density).
Proof strength non-proportional elongation is calculated as being the stress at the interception of the trace with a line drawn parallel to the linear portion line, offset by the specified percentage non-proportional elongation.
Proof strength total elongation is calculated as being the stress at the specified percentage total elongation.
The load for a given cross sectional area under which a material must not stretch permanently beyond a specified percentage of its length.
Peel and tear testing, defined as distance moved by the two parts as they separate.
Limit to which the test will drive.
A component or assembly which is so unlikely to become defective in a manner that will lower the intrinsic safety of the circuit that it may be considered not subject to fault when analysis or tests for intrinsic safety are made.
Rupture caused to a sample when the force is applied at 90 degrees to the sample.
The process of supplying an enclosure with clean air or an inert gas at sufficient flow and positive pressure to reduce, to an acceptable safe level, the concentration of any flammable gases or vapors initially present, and to maintain this safe level by positive pressure with or without continuous flow.
property of a phenomenon, body, or substance, where the property has a magnitude that can be expressed as a number and a reference
set of mathematical rules and operations applied to quantities other than ordinal quantities
dimension of a quantity
EXAMPLE 1: In the ISQ, the quantity dimension of force is denoted by dim F = LMT–2.
EXAMPLE 2: In the same system of quantities, dim ρB = ML–3 is the quantity dimension of mass concentration of component B, and ML–3 is also the quantity dimension of mass density, ρ, (volumic mass).
EXAMPLE 3: The period T of a pendulum of length l at a place with the local acceleration of free fall g is
T = C(g) √l
quantity for which all the exponents of the factors corresponding to the base quantities in its quantity dimension are zero
EXAMPLES: Plane angle, solid angle, refractive index, relative permeability, mass fraction, friction factor, Mach number. Number of turns in a coil, number of molecules in a given sample, degeneracy of the energy levels of a quantum system.
mathematical relation between quantities in a given system of quantities, independent of measurement units
value of a quantity
EXAMPLE 1: Length of a given rod
EXAMPLE 2: Mass of a given body
EXAMPLE 3: Curvature of a given arc
EXAMPLE 4: Celsius temperature of a given sample
EXAMPLE 5: Electric impedance of a given circuit element at a given frequency, where j is the imaginary unit
EXAMPLE 6: Refractive index of a given sample of glass
EXAMPLE 7: Rockwell C hardness of a given sample
EXAMPLE 8: Mass fraction of cadmium in a given
sample of copper
EXAMPLE 9: Molality of Pb2+ in a given sample of water
EXAMPLE 10: Arbitrary amount-of-substance concentration of lutropin in a given sample of human blood plasma (WHO International Standard 80/552 used as a calibrator)
ordered set of quantity values of quantities of a given kind of quantity used in ranking, according to magnitude, quantities of that kind
EXAMPLE 1: Celsius temperature scale.
EXAMPLE 2: Time scale.
EXAMPLE 3: Rockwell C hardness scale.
An enclosed channel designed for holding wires, cables, or busbars.
An enclosure so constructed, protected, or treated, as to prevent rain from interfering with the successful operation of the apparatus under specified test conditions.
An enclosure so constructed or protected that exposure to a beating rain will not result in the entrance of water under specified test conditions.
A data storage device that can be accessed in any order. It is known as a read/write memory, as information can be written into the memory, then read out when needed by the microprocessor. The contents of RAM are lost when the system is powered down.
component of measurement error that in replicate measurements varies in an unpredictable manner
absolute value of the difference between the extreme quantity values of a nominal indication interval
EXAMPLE: For a nominal indication interval of −10 V to +10 V, the range of the nominal indication interval is 20 V.
The range of the interval [a, b] is the difference b a and is denoted by r[a, b].
Timed rate of deformation when the sample is subjected to a constant load at a constant temperature.
Value of the slope of the relaxation curve at a given time.
operating condition that must be fulfilled during measurement in order that a measuring instrument or measuring system perform as designed
The opposition offered to the flow of alternating current by pure capacitance, pure inductance, or a combination of the two. Its unit is the “ohm”.
The ability of a material to recover to its original dimensions after being subjected to a force.
data related to a property of a phenomenon, body, or substance, or to a system of components of known composition or structure, obtained from an identified source, critically evaluated, and verified for accuracy
EXAMPLE: Reference data for solubility of chemical compounds as published by the IUPAC.
material, sufficiently homogeneous and stable with reference to specified properties, which has been established to be fit for its intended use in measurement or in examination of nominal properties
EXAMPLE 1: Examples of reference materials embodying quantities:
a) water of stated purity, the dynamic viscosity of
which is used to calibrate viscometers;
b) human serum without an assigned quantity value
for the amount-of-substance concentration of the
inherent cholesterol, used only as a
measurement precision control material;
c) fish tissue containing a stated mass fraction of a
dioxin, used as a calibrator.
EXAMPLE 2: Examples of reference materials embodying nominal properties:
a) colour chart indicating one or more specified
colours;
b) DNA compound containing a specified nucleotide
sequence;
c) urine containing 19-androstenedione.
measurement procedure accepted as providing measurement results fit for their intended use in assessing measurement trueness of measured quantity values obtained from other measurement procedures for quantities of the same kind, in calibration, or in characterizing reference materials
measurement standard designated for the calibration of other measurement standards for quantities of a given kind in a given organization or at a given location
operating condition prescribed for evaluating the performance of a measuring instrument or measuring system or for comparison of measurement results
quantity value used as a basis for comparison with values of quantities of the same kind
A force-measuring device whose characteristics are precisely known relative to a primary standard.
standard measurement uncertainty divided by the absolute value of the measured quantity value
Rate at which stress reduces due to creep.
A method of regulating the excitation voltage to the load cells. Some indicators compensate for voltage drops occurring between the indicator and load cells by increasing the indicator excitation output voltage; other indicators compensate for this voltage drop by amplifying the load cell return signal.
The maximum difference between load cell output readings for repeated loadings under identical loading and environmental conditions; the ability of an instrument, system, or method to give identical performance or results in successive instances.
condition of measurement, out of a set of conditions that includes the same measurement procedure, same operators, same measuring system, same operating conditions and same location, and replicate measurements on the same or similar objects over a short period of time
condition of measurement, out of a set of conditions that includes different locations, operators, measuring systems, and replicate measurements on the same or similar objects
Difference in extension before and after a material is stressed.
The ability of a material to return to its original shape after the removal of a stress that has produced elastic strain.
Opposition to current flow offered by a purely resistive component; simple opposition to current flow. Measured in ohms. See “reactance”.
The electrical resistance offered by a unit cube of material to the flow of direct current between opposite faces of the cube. It is measured in “ohm-centimeters”.
The smallest change in mechanical input which produces a detectable change in the output signal.
smallest change in a quantity being measured that causes a perceptible change in the corresponding indication
smallest difference between displayed indications that can be meaningfully distinguished
Radio frequency energy of sufficient magnitude to possibly affect operation of other electrical equipment.
The science of deformation and flow of matter.
The force required to deflect a ring or pipe sample by the percentage of its height or diameter.
A memory unit in which instructions or data are permanently stored for use by the machine or for reference by the user. The stored information is read out non-destructively and no information can subsequently be written into the memory.
A voltage-based serial method of data communication used to transfer data between digital devices. Two wires carry the data; one wire is signal ground, and several control wires may be used for handshaking. A logic “high” is from -3 to -25 volts and a logic “low” is from +3 to +25 volts. Transmission distance should be restricted to 50 feet.
It provides for data transmission, using balanced or differential signaling, with unidirectional/non-eversible, terminated or non-terminated transmission lines, point to point, or multi-drop. In contrast to RS-485 (which is multi-point instead of multidrop) RS-422 does not allow multiple drivers but only multiple receivers.
Can be used effectively over long distances and in electrically noisy environments. Multiple receivers may be connected to such a network in a linear, multi-drop configuration. These characteristics make such networks useful in industrial environments and similar applications.
When a sample bursts or is torn.
Value of force to cause a rupture / sample dimensions.
The failure of a specimen held under a definite constant load for a given period of time at a specific temperature.
A figure denoting the overload (and allowance thereof) a device can withstand before breaking down.
Measurement rate, in samples per second, that the A/D converter updates. Lower values are more immune to noise.
A device for weighing, comparing and determining weight or mass.
part of a displaying measuring instrument, consisting of an ordered set of marks together with any associated quantity values
Joint consisting of a line formed by joining two pieces.
A straight line that intersects a curve at two or more points.
Slope of a line drawn from the origin to a point on the stress / strain curve.
measurement standard established through calibration with respect to a primary measurement standard for a quantity of the same kind
property of a measuring system, used with a specified measurement procedure, whereby it provides measured quantity values for one or more measurands such that the values of each measurand are independent of other measurands or other quantities in the phenomenon, body, or substance being investigated
EXAMPLE 1: Capability of a measuring system including a mass spectrometer to measure the ion current ratio
generated by two specified compounds without disturbance by other specified sources of electric current.
EXAMPLE 2: Capability of a measuring system to measure the power of a signal component at a given frequency without being disturbed by signal components or other signals at other frequencies.
EXAMPLE 3: Capability of a receiver to discriminate between a wanted signal and unwanted signals, often having frequencies slightly different from the frequency of the wanted signal:
EXAMPLE 4: Capability of a measuring system for ionizing radiation to respond to a given radiation to be measured in the presence of concomitant radiation.
EXAMPLE 5: Capability of a measuring system to measure the amount-of-substance concentration of creatininium in blood plasma by a Jaffé procedure without being influenced by the glucose, urate, ketone, and protein concentrations.
EXAMPLE 6: Capability of a mass spectrometer to measure the amount-of-substance abundance of the 28Si isotope and of the 30Si isotope in silicon from a geological deposit without influence between the two, or from the 29Si isotope.
Compensates for the resistance changes in the copper wiring. Sensing compares the supplied excitation voltage to the applied excitation voltage at the load cell.
The ratio of the change in output to the change in mechanical input.
Refers to how the change in temperature can affect the performance of the balance.
quotient of the change in an indication of a measuring system and the corresponding change in a value of a quantity being measured
element of a measuring system that is directly affected by a phenomenon, body, or substance carrying a quantity to be measured
EXAMPLES: Sensing coil of a platinum resistance thermometer, rotor of a turbine flow meter, Bourdon tube of a pressure gauge, float of a level-measuring instrument, photocell of a spectrometer, thermotropic liquid crystal which changes colour as a function of temperature.
A method of data transmission in which each bit of information is sent sequentially on a single channel.
In a feedback control loop, the point which determines the desired value of the quantity being controlled.
A force acting perpendicular to the longitudinal axis of a sample.
A bending beam load cell in which the strain gauges are mounted on a thin web of material in a machined-out cavity in the load cell.
Shear rate is a measure of the rate of shear deformation.
Maximum shear stress that can be sustained by a material before rupture.
Normal stress is perpendicular to the designated plane, shear stress is parallel to the plane.
The shield is used to protect the signal from RFI/EMI and needs to be grounded at one end. The shield wire is not connected to the load cell housing, but instead terminated at the indicator.
A test intended to disclose the weighing performance of a scale under off-center loading.
Any load acting 90° to the primary axis at the point of axial load applications.
This is the actual millivolt output of the load cell. The signal wires are connected to the A/D of the indicator. It is here where the analog signal is converted to digital. Signal strength is references in microvolts per graduation.
A method of matching load cell outputs in a multicell system by adjusting the output signal voltage through a variable resistor placed across the signal leads.
A flat, molded component package having terminal lugs along one side; half of a dual inline package (DIP).
Used in the testing of container lids, the action of removing the lid that exhibits a sharp drop in.
Used in the testing of container lids, the action of fitting the lid that exhibits a sharp drop in force.
The difference between the highest value and the lowest value.
Utilizing two calibration points; one at zero and a choice of either half capacity or full capacity.
Statistical Process Control.
The elasticity of a material that can be stretched and returns to its original length.
property of a measuring instrument, whereby its metrological properties remain constant in time
EXAMPLE 1: In terms of the duration of a time interval over which a metrological property changes by a stated amount.
EXAMPLE 2 In terms of the change of a property over a stated time interval
The time required to ensure that any further change in the parameter being measured is tolerable.
A temporary storage area in a computer memory consisting of a small group of registers. Data stored in the stack is retrieved from the stack in reverse order in which it is stored.
measurement uncertainty expressed as a standard deviation
reference data issued by a recognized authority
EXAMPLE 1: Values of the fundamental physical constants, as regularly evaluated and recommended by CODATA of ICSU.
EXAMPLE 2: Relative atomic mass values, also called atomic weight values, of the elements, as evaluated every two years by IUPAC-CIAAW, approved by the IUPAC General Assembly, and published in Pure Appl. Chem.
The environmental conditions under which measurements should be made, when measurements under any other conditions may result in disagreement between various observers at different times and places. The conditions are as follows: Temperature: 72 degrees plus 3.6 degrees F (23 degrees plus or minus 2 degrees C) Barometric Pressure: 28 to 32 inches Hg.
Capacity as a percentage of nominal load limit capacity, in which the load cell can safely be loaded to this limit with no adverse affect on the performance or any change in its zero balance or other specifications.
Rods installed to rigidly restrain a vessel or other weighing system component in the horizontal position. They will have little effect on the accuracy of the system when installed properly.
operating condition of a measuring instrument or measuring system in which the relation established by calibration remains valid even for a measurand varying with time
duration between the instant when an input quantity value of a measuring instrument or measuring system is subjected to an abrupt change between two specified constant quantity values and the instant when a corresponding indication settles within specified limits around its final steady value
Stiffness is the resistance of an elastic body to deflection by an applied force.
The amount of deformation a material experiences per unit of original length in response to stress.
Measure of energy absorption characteristics of a material under load up to fracture.
A device for detecting the strain that a certain force produces on a body. The gauge consists of one or more fine wires cemented to the surface under test. As the surface becomes strained, the wires stretch or compress, changing their resistance. Several strain gauges are used to make up a load cell.
An increase in hardness and strength caused by plastic deformation at temperatures below the recrystallization range.
Deformation of a specimen height or length per time.
The of stress an object can endure before it breaks.
Force that a material is subjected to per unit of original area.
The algebraic ratio of two specified stress values in a stress cycle.
A stress-strain condition in which the stress reduces as the strain remains constant.
The property of an adhesive which causes it to form filaments, threads, etc., when the applicator is removed from the adherend, or when transfer surfaces are separated.
measurement unit obtained by dividing a given measurement unit by an integer greater than one
EXAMPLE 1: The millimetre is a decimal submultiple of the metre.
EXAMPLE 2: For a plane angle, the second is a nondecimal submultiple of the minute.
set of quantities together with a set of noncontradictory equations relating those quantities
set of base units and derived units, together with their multiples and submultiples, defined in accordance with given rules, for a given system of quantities
component of measurement error that in replicate measurements remains constant or varies in a predictable manner
Applicable to adhesives. Two surfaces are contacted together at a set speed for a set duration and the force required to pull them apart is recorded.
The instantaneous slope at any point on the stress-strain curve.
The weight of an empty container or vehicle, or the allowance or deduction from gross weight made on account thereof.
measurement uncertainty specified as an upper limit and decided on the basis of the intended use of measurement results
Resistance of a material to a force acting to initiate and then propagate a failure.
The force required to tear an sample divided by the sample thickness.
A figure which states the extent to which a quantity drifts under the influence of temperature.
The change in rated output due to a change in ambient temperature. Usually expressed as the percentage change in rated output per 100°F change in ambient temperature.
The change in zero balance due to a change in ambient temperature. Usually expressed as the change in zero balance in percent of rated output per 100°F change in ambient temperature.
The range of temperatures over which the load cell is compensated to maintain rated output and zero balance within specific limits.
The extremes of temperatures within which the load cell will operate without permanent adverse change to any of its performance characteristics.
Strength of fiber or yarn in terms of the ratio of breaking load and linear density.
The stress in force per unit area required to break a specimen.
Extent to which vulcanized rubber is permanently deformed after being stretched a specified amount for a short time.
The resistance of the load cell circuit measured at specific adjacent bridge terminals at standard temperature with no load applied and with the excitation and output terminals open-circuited.
The resistance of the load cell circuit measured at the excitation terminals at standard temperature with no load applied and with the output (signal) terminals open-circuited.
The resistance of the load cell circuit measured at the output signal terminals at standard temperature with no load applied and with the excitation terminals open-circuited.
A unit for linear density equal to the mass in grams per 1000M.
The amount of error that is allowed in a value. It is usually expressed as a percent of nominal value, plus or minus so many units of measurement.
The ability of a material to absorb energy and deform plastically before fracturing.
Texture Profile Analysis. A simulation of a two bite action.
The step-by-step transfer process by which the load cell calibration can be related to primary standards.
A device that converts energy from one form to another.
device used as an intermediary to compare measurement standards
A momentary surge on a signal or power line. It may produce false signals or triggering impulses and cause insulation or component breakdowns and failures.
measurement standard, sometimes of special construction, intended for transport between different locations
EXAMPLE: Portable battery-operated caesium-133 frequency measurement standard.
A three-terminal, gate controlled, bidirectional silicon switching device that can switch either alternating or direct currents.
To make a fine adjustment, as of load cell outputs in a multicell system.
quantity value consistent with the definition of a quantity
Instantaneous percentage change in specimen length. It is equal to the natural log of the ratio of length at any instant to original length.
the applied load divided by the actual cross-sectional area (the changing area with respect to time) of the specimen at that load. Engineering strain is the amount that a material deforms per unit length in a tensile test. Also known as nominal strain.
evaluation of a component of measurement uncertainty determined by means other than a Type A evaluation of measurement uncertainty
EXAMPLES: Evaluation based on information
— associated with authoritative published quantity values,
— associated with the quantity value of a certified reference material,
— obtained from a calibration certificate,
— about drift,
— obtained from the accuracy class of a verified measuring instrument,
— obtained from limits deduced through personal experience.
evaluation of a component of measurement uncertainty by a statistical analysis of measured quantity values obtained under defined measurement conditions
statement of a measurement uncertainty, of the components of that measurement uncertainty, and of their calculation and combination
mathematical relation between base units, coherent derived units or other measurement units
EXAMPLE 1 : For the quantities in Example 1 of item 1.22, [Q1] = [Q2] [Q3] where, [Q1], [Q2], and [Q3] denote
the measurement units of Q1, Q2, and Q3, respectively, provided that these measurement units are in a coherent
system of units.
EXAMPLE 2 J := kg m2/s2, where, J, kg, m, and s are the symbols for the joule, kilogram, metre, and second,
respectively. (The symbol := denotes “is by definition equal to” as given in the ISO 80000 and IEC 80000
series.)
EXAMPLE 3: 1 km/h = (1/3.6) m/s.
The unit of measure that is to be represented. lb, kg, oz, etc.
A specification to establish communication between devices and a host controller (usually personal computers).
A parameter used to select load cells for NTEP approved applications. For single cell applications, vmin must be less than or equal to the scale division size; for mechanical scale conversions using one load cell, vmin must be less than or equal to the scale division size divided by the scale multiple. For a scale using more than one load cell, vmin must be less than or equal to the scale division divided by the square root of the number of cells.
verification, where the specified requirements are adequate for an intended use
EXAMPLE: A measurement procedure, ordinarily used for the measurement of mass concentration of nitrogen in water, may be validated also for measurement of mass concentration of nitrogen in human serum.
difference in indication for a given measured quantity value, or in quantity values supplied by a material measure, when an influence quantity assumes successively two different quantity values
provision of objective evidence that a given item fulfills specified requirements
EXAMPLE 1: Confirmation that a given reference material as claimed is homogeneous for the quantity value and measurement procedure concerned, down to a measurement portion having a mass of 10 mg.
EXAMPLE 2: Confirmation that performance properties or legal requirements of a measuring system are achieved.
EXAMPLE 3: Confirmation that a target measurement uncertainty can be met.
International Vocabulary of Basic and General Terms in Metrology (1993)
International Vocabulary of Metrology — Basic and General Concepts and Associated Terms (this publication) VIM
International Vocabulary of Terms in Legal Metrology
A computer storage medium whose contents are lost when there is a loss of power.
The unit of voltage, potential difference and electromotive force. One volt will send a current of one ampere through a resistance of one ohm.
The electrical potential difference that exists between two points and is capable of producing a flow of current when a closed circuit is connected between the two points.
A temporary decrease in voltage level lasting at least one alternating current cycle.
Large damaging voltage pulse caused when lightning strikes a power line, communication line, a signal or sensing line, or even the ground nearby.
A temporary rise in voltage level lasting at least one alternating current cycle.
An earth connection made by running a strong wire to the nearest cold water pipe.
An enclosure so constructed that moisture will not enter the enclosure under specified test conditions.
An enclosure so constructed or protected that exposure to the weather will not interfere with successful operation of its contained equipment.
The force or amount of gravitational pull by which an object or body is attracted toward the center of the earth.
World Health Organization
measurement standard that is used routinely to calibrate or verify measuring instruments or measuring systems
A semiconductor diode which is used in the reverse biased condition. It exhibits a nondestructive breakdown at a predetermined reverse voltage, so while the diode is operating in this breakdown region, an increase in current flow through the diode will not result in increased voltage drop across the diode. It is used in voltage regulation circuits and as a voltage limiting device in intrinsic safety barriers.
adjustment of a measuring system so that it provides a null indication corresponding to a zero value of a quantity to be measured
The output signal of the load cell with rated Excitation and with no load applied, usually expressed in percent of Rated Output.
datum measurement error where the specified measured quantity value is zero
By pressing the tare key, the scale display returns to zero.
This is the range in which the scale can be zeroed. A selection of 1.9% means that the scale will zero off any weight within + or – 1.9% of the calibrated zero point.
The difference in Zero Balance measured immediately before Rated Load application of specified duration, measured after removal of the load, and when the output has stabilized.
A permanent change in no-load output.
The degree to which the load cell maintains its Zero Balance with all environmental conditions and other variables remaining constant.
Automatically zeros off the scale within the specified range. Zero track band is most commonly used to zero off the buildup of water, ice, and snow on a scale.