Handbook 44 – 2022 Appendix D – Definitions

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Table of Contents

Appendix D. Definitions................... D-5

A .......................................................... D-5

absolute value. .............................................. D-5

acceptance test. ............................................. D-5

accurate......................................................... D-5

all-class. ........................................................ D-5

analog or digital recorder.............................. D-5

analog type.................................................... D-5

animal scale. ................................................. D-5

apparent mass versus 8.0 g/cm3. ................... D-5

approval seal................................................. D-5

assumed atmospheric pressure...................... D-5

audit trail....................................................... D-5

automatic bulk weighing system................... D-5

automatic checkweigher ............................... D-6

automatic gravimetric filling machine 

(instrument).............................................. D-6

automatic-indicating scale. ........................... D-6

automatic temperature or density compensation.

................................................................. D-6

automatic weighing system (AWS). ............. D-6

automatic zero-setting mechanism (AZSM). D-6

automatic zero-setting mechanism (beltconveyor scale). ....................................... D-6

automatic zero-tracking (AZT) mechanism.. D-6

auxiliary indicator......................................... D-6

axle-load scale. ............................................. D-6

B........................................................... D-7

badge............................................................. D-7

balance, zero-load......................................... D-7

balance indicator........................................... D-7

balancing mechanism.................................... D-7

base pressure................................................. D-7

basic distance rate......................................... D-7

basic time rate............................................... D-7

basic tolerances............................................. D-7

batching system. ........................................... D-7

batching meter .............................................. D-7

beam. ............................................................ D-7

beam scale. ................................................... D-7

bell prover..................................................... D-7

belt-conveyor................................................ D-7

belt-conveyor scale ....................................... D-7

belt-conveyor scale systems area.................. D-7

belt load. ....................................................... D-7

belt revolution............................................... D-8

billed weight. ................................................ D-8

binary submultiples....................................... D-8

built-for-purpose device................................ D-8

C .......................................................... D-8

calibration parameter. ................................... D-8

carbon dioxide liquid-measuring device....... D-8

car-wash timer. ............................................. D-8

center-reading tank. ...................................... D-8

cereal grain and oil seeds.............................. D-8

chart recorder................................................ D-8

check rate...................................................... D-8

checkweighing scale. .................................... D-8

class of grain................................................. D-8

clear interval between graduations. .............. D-8

cleared........................................................... D-8

cold-tire pressure. ......................................... D-9

commercial equipment.................................. D-9

computing scale. ........................................... D-9

computing type or computing type device.... D-9

concave curve. .............................................. D-9

concentrated load capacity (CLC) ................ D-9

configuration parameter................................ D-9

consecutive-car test train. ............................. D-9

construction materials hopper scale.............. D-9

contract sale. ................................................. D-9

conventional scale......................................... D-9

conversion table............................................ D-9

convex curve................................................. D-9

conveyor stringers......................................... D-9

correct........................................................... D-9

correction table. .......................................... D-10

counterbalance weight(s)............................ D-10

counterpoise weight(s)................................ D-10

coupled-in-motion railroad weighing system.

............................................................. ..D-10

crane scale. ................................................. D-10

cryogenic liquid-measuring device............. D-10

cryogenic liquids......................................... D-10

cubic foot, gas............................................. D-10

D ........................................................ D-10

“d,” dimension division value..................... D-10

d, value scale division................................. D-10

Dmax (maximum load of the measuring range).

.............................................................. .D-10

Dmin (minimum load of the measuring range).

............................................................. ..D-10

data acquisition time (DAT). ...................... D-10

dairy-product-test scale............................... D-10

decimal submultiples. ................................. D-11

decreasing-load test. ................................... D-11

deficiency. .................................................. D-11

diesel gallon equivalent (DGE)................... D-11

digital type.................................................. D-11
Appendix D – Definitions Handbook 44 – 2022

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dimensional offset....................................... D-11

dimensional weight (or dim, weight).......... D-11

direct sale.................................................... D-11

discharge hose............................................. D-11

discharge line.............................................. D-11

discrimination (of an automatic-indicating 

scale). ..................................................... D-11

dispenser..................................................... D-11

distributed-car test train. ............................. D-11

dry hose. ..................................................... D-11

dry-hose type. ............................................. D-11

dynamic monorail weighing system ........... D-12

E......................................................... D-12

e, value of verification scale division. ........ D-12

Emax (maximum capacity). .......................... D-12

Emin (minimum dead load). ......................... D-12

emin (minimum verification scale division). D-12

electronic link. ............................................ D-12

element. ...................................................... D-12

equal-arm scale........................................... D-12

equipment, commercial............................... D-12

event counter............................................... D-12

event logger. ............................................... D-12

excess and deficiency ................................. D-13

extras........................................................... D-13

F......................................................... D-13

face. ............................................................ D-13

fare.............................................................. D-13

farm milk tank. ........................................... D-13

feeding mechanism..................................... D-13

ft3/h. ............................................................ D-13

fifth wheel................................................... D-13

fifth-wheel test............................................ D-13

flat rate........................................................ D-13

fractional bar............................................... D-13

G........................................................ D-13

gasoline gallon equivalent (GGE)............... D-13

gauge pressure. ........................................... D-13

gauge rod. ................................................... D-14

gauging. ...................................................... D-14

graduated interval. ...................................... D-14

graduation................................................... D-14

grain class. .................................................. D-14

grain hopper scale....................................... D-14

grain moisture meter................................... D-14

grain sample................................................ D-14

grain-test scale. ........................................... D-14

grain type.................................................... D-14

gravity discharge......................................... D-14

H........................................................ D-14

head pulley.................................................. D-14

hexahedron. ................................................ D-14

hired............................................................ D-14

hopper scale. ............................................... D-14

I.......................................................... D-14

idlers or idler rollers. .................................. D-14

idler space................................................... D-15

increasing-load test..................................... D-15

increment. ................................................... D-15

index of an indicator................................... D-15

indicating element....................................... D-15

indicator, balance........................................ D-15

initial distance or time interval. .................. D-15

initial zero-setting mechanism.................... D-15

in-service light indicator............................. D-15

integrator..................................................... D-15

interval, clear, between graduations. .......... D-15

interval, graduated. ..................................... D-15

irregularly-shaped object. ........................... D-15

J ......................................................... D-15

jewelers’ scale............................................. D-15

K........................................................ D-15

kind of grain................................................ D-15

L......................................................... D-15

label. ........................................................... D-15

large-delivery device. ................................. D-15

laundry-drier timer...................................... D-16

liquefied petroleum gas............................... D-16

liquefied petroleum gas liquid-measuring 

device. .................................................... D-16

liquefied petroleum gas vapor-measuring device.

............................................................... D-16

liquid fuel.................................................... D-16

liquid-fuel device........................................ D-16

liquid-measuring device.............................. D-16

liquid volume correction factor................... D-16

livestock scale............................................. D-16

load cell. ..................................................... D-16

load cell verification interval (v). ............... D-16

loading point............................................... D-16

load-receiving element................................ D-16

location services ......................................... D-16

low-flame test. ............................................ D-16

lubricant device........................................... D-16

M ....................................................... D-17

m3/h............................................................. D-17

main bar...................................................... D-17

main graduation. ......................................... D-17

main-weighbeam elements. ........................ D-17

manual zero-setting mechanism.................. D-17

manufactured device................................... D-17

mass flow meter.......................................... D-17

master meter test method............................ D-17

master weight totalizer................................ D-17

material test................................................. D-17
Handbook 44 – 2022 Appendix D – Definitions

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maximum capacity...................................... D-17

maximum cargo load. ................................. D-17

measurement field....................................... D-17

measuring element...................................... D-17

meter register. ............................................. D-17

metrological integrity (of a device). ........... D-18

minimum capacity. ..................................... D-18

minimum clear interval............................... D-18

minimum delivery....................................... D-18

minimum load cell verification interval. – See 

vmin ......................................................... D-18

minimum measured quantity (MMQ)......... D-18

minimum tolerance..................................... D-18

minimum totalized load. ............................. D-18

moisture content (wet basis). ...................... D-18

money drop................................................. D-18

money-operated type. ................................. D-18

motor-fuel................................................... D-18

motor-fuel device or motor-fuel dispenser or 

retail motor-fuel device.......................... D-18

multi-class................................................... D-18

multi-interval scale. .................................... D-18

multi-jet water meter................................... D-19

multiple....................................................... D-19

multiple cell application load cell............... D-19

multiple range scale.................................... D-19

multiple of a scale....................................... D-19

multi-revolution scale. ................................ D-19

multiple-tariff taximeter.............................. D-19

N............................................................ D-19

NBP. ........................................................... D-19

NTP............................................................. D-19

NTP density and volume correction factor. D-19

natural gas................................................... D-19

negotiated rate............................................. D-19

nmax (maximum number of scale divisions). D-19

no-load reference value............................... D-20

nominal....................................................... D-20

nominal capacity......................................... D-20

nominal capacity, batching scale. ............... D-20

nominal capacity, hopper scale................... D-20

non-automatic checkweigher...................... D-20

non-automatic weighing instrument. .......... D-20

non-resettable totalizer................................ D-20

nonretroactive. ............................................ D-21

nose-iron..................................................... D-21

notes............................................................ D-21

O........................................................ D-21

odometer..................................................... D-21

official grain samples.................................. D-21

official with statutory authority. ................. D-21

operating tire pressure................................. D-21

over-and-under indicator. ........................... D-21

overregistration and underregistration. ....... D-21

P......................................................... D-22

parallax. ...................................................... D-22

parking meter.............................................. D-22

passenger vehicles. ..................................... D-22

performance requirements. ......................... D-22

point-based railroad weighing systems....... D-22

point-of-sale system.................................... D-22

poise............................................................ D-22

postal scale.................................................. D-22

prepackaging scale...................................... D-22

prescription scale. ....................................... D-22

pressure type (device)................................. D-22

primary indicating or recording elements... D-22

prover method............................................. D-23

prover oil. ................................................... D-23

proving indicator......................................... D-23

R ........................................................ D-23

“r” factor..................................................... D-23

radio frequency interference (RFI). ............ D-23

random error(s)........................................... D-23

ranges, weight............................................. D-23

rated capacity.............................................. D-23

rated scale capacity..................................... D-23

ratio test. ..................................................... D-23

reading face................................................. D-23

reading-face capacity.................................. D-24

recorded representation............................... D-24

recording element. ...................................... D-24

recording scale............................................ D-24

reference weight car.................................... D-24

reference vehicle......................................... D-24

remanufactured device................................ D-24

remanufactured element.............................. D-24

remote configuration capability.................. D-24

repaired device............................................ D-24

repaired element ......................................... D-24

retail device................................................. D-24

retroactive................................................... D-24

road test. ..................................................... D-25

rolling circumference.................................. D-25

S......................................................... D-25

scale. ........................................................... D-25

scale area, belt-conveyor ............................ D-25

scale division, number of (n). ..................... D-25

scale division, value of (d).......................... D-25

scale section................................................ D-25

seal.............................................................. D-25

section capacity........................................... D-25

section test. ................................................. D-25

security means. ........................................... D-25

security seal. ............................................... D-25

selector-type................................................ D-25

semi-automatic zero-setting mechanism..... D-25
Appendix D – Definitions Handbook 44 – 2022

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sensitivity (of a nonautomatic-indicating scale).

............................................................... D-25

sensitivity requirement (SR). ...................... D-26

shift test. ..................................................... D-26

side.............................................................. D-26

simulated-road test...................................... D-26

simulated test. ............................................. D-26

single cell application load cell................... D-26

single-tariff taximeter. ................................ D-26

skirting........................................................ D-26

slow-flow meter.......................................... D-26

small-delivery device.................................. D-26

span (structural). – ...................................... D-26

specification................................................ D-26

static monorail weighing system................. D-26

strain-load test............................................. D-26

subordinate graduation................................ D-26

subsequent distance or time intervals ......... D-26

substitution test........................................... D-26

substitution test load. .................................. D-27

surface gauge. ............................................. D-27

systematic (average) error........................... D-27

T......................................................... D-27

tail pulley.................................................... D-27

take-up. ....................................................... D-27

tare mechanism........................................... D-27

tare-weighbeam elements. .......................... D-27

taximeter..................................................... D-27

test chain..................................................... D-27

test liquid. ................................................... D-27

test object.................................................... D-27

test puck...................................................... D-27

test train. ..................................................... D-27

test weight car............................................. D-28

testing. ........................................................ D-28

time recorder............................................... D-28

timing device. ............................................. D-28

tolerance. .................................................... D-28

training idlers.............................................. D-28

transfer standard. ........................................ D-28

tripper. ........................................................ D-28

U ........................................................ D-28

uncoupled-in-motion railroad weighing system.

............................................................... D-28

underregistration......................................... D-28

unit price..................................................... D-28

unit train...................................................... D-28

unit weight.................................................. D-28

user requirement. ........................................ D-28

usual and customary. .................................. D-28

utility-type water meter. .............................. D-29

V ........................................................ D-29

value of minimum graduated interval......... D-29

vapor equalization credit............................. D-29

vapor equalization line................................ D-29

vehicle on-board weighing system. ............ D-29

vehicle scale................................................ D-29

verification scale division, value of (e)....... D-29

visible type.................................................. D-29

vmin (minimum load cell verification interval).

.............................................................. .D-29

W ....................................................... D-29

weighbeam.................................................. D-29

weigh-belt system....................................... D-29

weighing element........................................ D-29

weigh-in-motion (WIM) vehicle scale........ D-30

weigh-labeler.............................................. D-30

weigh module ............................................. D-30

weighment. ................................................. D-30

weight, unit................................................. D-30

weight classifier.......................................... D-30

weight ranges.............................................. D-30

wet basis. .................................................... D-30

wet hose...................................................... D-30

wet-hose type.............................................. D-30

wheel-load weighers. .................................. D-30

wholesale device......................................... D-30

wing pulley. ................................................ D-30

Z......................................................... D-30

zero-load balance........................................ D-30

zero-load balance, automatic-indicating scale..

............................................................... D-30

zero-load balance, nonautomatic-indicating 

scale........................................................ D-31

zero-load balance for a recording scale. ..... D-31

zero-load reference (belt-conveyor scales). D-31

zero-setting mechanism. ............................. D-31

automatic zero-setting mechanism (AZSM).D-31

automatic zero-tracking (AZT) mechanism. D-31

initial zero-setting mechanism..................... D-31

manual zero-setting mechanism. ................. D-31

semiautomatic zero-setting mechanism....... D-31

zero-setting mechanism (belt-conveyor scale)..

............................................................... D-31

zero-tracking mechanism............................ D-31

zone of uncertainty. .................................... D-31
Handbook 44 – 2022 Appendix D – Definitions

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Appendix D. Definitions

The specific code to which the definition applies is shown in [brackets] at the end of the definition. Definitions for 

the General Code [1.10] apply to all codes in Handbook 44.

A

absolute value. – The absolute value of a number is the magnitude of that number without considering the positive or 

negative sign. [2.20]

acceptance test. – The first official test of a farm milk tank, at a particular location, in which the tank is accepted as 

correct. This test applies to newly constructed tanks, relocated used tanks, and recalibrated tanks. [4.42]

accurate. – A piece of equipment is “accurate” when its performance or value – that is, its indications, its deliveries, 

its recorded representations, or its capacity or actual value, etc., as determined by tests made with suitable 

standards - conforms to the standard within the applicable tolerances and other performance requirements. Equipment 

that fails so to conform is “inaccurate.” (Also see “correct.”) [Appendix A]

all-class. – A description of a multi-class calibration that includes all the classes of a grain type. [5.56(a), 5.57]

(Added 2007)

analog or digital recorder. – An element used with a belt-conveyor scale that continuously records the rate-of-flow 

of bulk material over the scale (formerly referred to as a chart recorder). [2.21]

(Amended 1989)

analog type. – A system of indication or recording in which values are presented as a series of graduations in 

combination with an indicator, or in which the most sensitive element of an indicating system moves continuously 

during the operation of the device. [1.10]

animal scale. – A scale designed for weighing single heads of livestock. [2.20]

(Amended 1987)

apparent mass versus 8.0 g/cm3

. – The apparent mass of an object versus 8.0 g/cm3 is the mass of material of density 

8.0 g/cm3 that produces exactly the same balance reading as the object when the comparison is made in air with a 

density of 1.2 mg/cm3 at 20 °C. [3.37]

approval seal. – A label, tag, stamped or etched impression, or the like, indicating official approval of a device. (Also 

see “security seal.”) [1.10]

assumed atmospheric pressure. – The average atmospheric pressure agreed to exist at the meter at various ranges of 

elevation, irrespective of variations in atmospheric pressure from time to time. [3.33]

audit trail. – An electronic count and/or information record of the changes to the values of the calibration or 

configuration parameters of a device. [1.10, 2.20, 2.21, 2.24, 3.30, 3.31, 3.32, 3.34, 3.35, 3.36, 3.37, 3.38, 3.39, 5.54, 

5.56(a), 5.58]

(Added 1993) (Amended 2019)

automatic bulk weighing system. – A weighing system adapted to the automatic weighing of bulk commodities in 

successive drafts of predetermined amounts, automatically recording the no-load and loaded weight values and 

accumulating the net weight of each draft. [2.22]
Appendix D – Definitions Handbook 44 – 2022

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automatic checkweigher. – An automatic weighing system that does not require the intervention of an operator during 

the weighing process and used to subdivide items of different weights into one or more subgroups, such as identifying 

packages that have acceptable or unacceptable fill levels according to the value of the difference between their weight 

and a pre-determined set point. These systems may be used to fill standard packages for compliance with net weight 

requirements. [2.24]

(Amended 2004)

automatic gravimetric filling machine (instrument). – A filling machine or instrument that fills containers or 

packages with predetermined and virtually constant mass of product from bulk by automatic weighing, and which 

comprises essentially an automatic feeding device or devices associated with one or more weighing unit and the 

appropriate discharge devices. [2.24]

(Added 2004)

automatic-indicating scale. – One on which the weights of applied loads of various magnitudes are automatically 

indicated throughout all or a portion of the weighing range of the scale. (A scale that automatically weighs out 

commodity in predetermined drafts, such as an automatic hopper scale, a packaging scale, and the like, is not an 

“automatic-indicating” scale.) [2.20. 2.22]

automatic temperature or density compensation. – The use of integrated or ancillary equipment to obtain from the 

output of a volumetric meter an equivalent mass, or an equivalent liquid volume at the assigned reference temperature 

below and a pressure of 14.696 lb/in2 absolute.

Cryogenic liquids 21 °C (70 °F) [3.34]

Hydrocarbon gas vapor 15 °C (60 °F) [3.33]

Hydrogen gas 21 °C (70 °F) [3.39]

Liquid carbon dioxide 21 °C (70 °F) [3.38]

Liquefied petroleum gas (LPG) and Anhydrous ammonia 15 °C (60 °F) [3.32]

Petroleum liquid fuels and lubricants 15 °C (60 °F) [3.30]

(Amended 2019)

automatic weighing system (AWS). – An automatic weighing system is a weighing device that, in combination with 

other hardware and/or software components, automatically weighs discrete items and that does not require the 

intervention of an operator during the weighing process. Examples include, but are not limited to, weigh-labelers and 

checkweighers. [2.24]

(Amended 2004)

automatic zero-setting mechanism (AZSM). – See “automatic zero-setting mechanism” under “zero-setting 

mechanism.” [2.22]

(Amended 2010)

automatic zero-setting mechanism (belt-conveyor scale). – A zero setting device that operates automatically 

without intervention of the operator after the belt has been running empty. [2.21]

(Added 2002)

automatic zero-tracking (AZT) mechanism. – Automatic means provided to maintain the zero-balance indication, 

within specified limits, without the intervention of an operator. [2.20, 2.22, 2.24]

(Amended 2010)

auxiliary indicator. – Any indicator other than the master weight totalizer that indicates the weight of material 

determined by the scale. [2.21]

axle-load scale. – A scale permanently installed in a fixed location, having a load-receiving element specially adapted 

to determine the combined load of all wheels (1) on a single axle or (2) on a tandem axle of a highway vehicle. [2.20]
Handbook 44 – 2022 Appendix D – Definitions

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B

badge. – A metal plate affixed to the meter by the manufacturer showing the manufacturer’s name, serial number and 

model number of the meter, and its rated capacity. [3.33]

balance, zero-load. – See “zero-load balance.” [2.20]

balance indicator. – A combination of elements, one or both of which will oscillate with respect to the other, for 

indicating the balance condition of a nonautomatic indicating scale. The combination may consist of two indicating 

edges, lines, or points, or a single edge, line, or point and a graduated scale. [2.20]

balancing mechanism. – A mechanism (including a balance ball) that is designed for adjusting a scale to an accurate 

zero-load balance condition. [2.20]

base pressure. – The absolute pressure used in defining the gas measurement unit to be used, and is the gauge pressure 

at the meter plus an agreed atmospheric pressure. [3.33]

basic distance rate. – The charge for distance for all intervals except the initial interval. [5.54]

basic time rate. – The charge for time for all intervals except the initial interval. [5.54]

basic tolerances. – Tolerances on underregistration and on overregistration, or in excess and in deficiency, that are 

established by a particular code for a particular device under all normal tests, whether maintenance or acceptance. 

Basic tolerances include minimum tolerance values when these are specified. Special tolerances, identified as such 

and pertaining to special tests, are not basic tolerances. [2.20, 2.22., 3.34, 3.38, 4.42, 5.54]

batching system. – One in which raw materials are proportioned in pre-determined quantities by weight and/or liquid 

measure for inclusion in a finished product. [2.22, 3.36]

(Added 2018)

batching meter. – A device used for the purpose of measuring quantities of water to be used in a batching operation.

[3.36]

beam. – See “weighbeam.” [2.20]

beam scale. – One on which the weights of loads of various magnitudes are indicated solely by means of one or more 

weighbeam bars either alone or in combination with counterpoise weights. [2.20]

bell prover. – A calibrated cylindrical metal tank of the annular type with a scale thereon that, in the downward travel 

in a surrounding tank containing a sealing medium, displaces air through the meter being proved or calibrated. [3.33]

belt-conveyor. – An endless moving belt for transporting material from place to place. [2.21]

belt-conveyor scale. – A device that employs a weighing element in contact with a belt to sense the weight of the 

material being conveyed and the speed (travel) of the material, and integrates these values to produce total delivered 

weight. [2.21]

belt-conveyor scale systems area. – The scale system area refers to the scale suspension, weigh idlers attached to the 

scale suspension, 5 approach (−) idlers, and 5 retreat (+) idlers. [2.21]

(Added 2001)

belt load. – The weight of the material carried by the conveyor belt, expressed in terms of weight units per unit of 

length (e.g., pounds per foot, kilograms per meter). Also called “belt loading.” [2.21]

(Added 2013)
Appendix D – Definitions Handbook 44 – 2022

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belt revolution. – The amount of conveyor belt movement or travel that is equivalent to the total length of the 

conveyor belt. Also referred to as "belt circuit." [2.21]

(Added 2013)

billed weight. – The weight used in the computation of the freight, postal, or storage charge, whether actual weight 

or dimensional weight. [5.58]

binary submultiples. – Fractional parts obtained by successively dividing by the number two. Thus, one-half, 

one-fourth, one-eighth, one-sixteenth, and so on, are binary submultiples. [1.10]

built-for-purpose device. – Any main device or element which was manufactured with the intent that it be used as, 

or part of, a weighing or measuring device or system. [1.10]

(Added 2003)

C

calibration parameter. – Any adjustable parameter that can affect measurement or performance accuracy and, due 

to its nature, needs to be updated on an ongoing basis to maintain device accuracy (e.g., span adjustments, linearization 

factors, and coarse zero adjustments). [2.20, 2.21, 2.24, 3.30, 3.31, 3.32, 3.34, 3.35, 3.36, 3.37, 3.38, 3.39, 5.54, 

5.56(a), 5.58.]

(Added 1993) (Amended 2016 and 2019)

carbon dioxide liquid-measuring device. – A system including a mechanism or machine of (a) the meter or (b) a 

weighing type of device mounted on a vehicle designed to measure and deliver liquid carbon dioxide. Means may be 

provided to indicate automatically, for one of a series of unit prices, the total money value of the quantity measured.

[3.38]

car-wash timer. – A timer used in conjunction with a coin-operated device to measure the time during which car-wash 

water, cleaning solutions, or waxing solutions are dispensed. [5.55]

center-reading tank. – One so designed that the gauge rod or surface gauge, when properly positioned for use, will 

be approximately in the vertical axis of the tank, centrally positioned with respect to the tank walls. [4.43]

cereal grain and oil seeds. – Agricultural commodities including, but not limited to, corn, wheat, oats, barley, flax, 

rice, sorghum, soybeans, peanuts, dry beans, safflower, sunflower, fescue seed, etc. [5.56(a), 5.56(b)]

chart recorder. – See analog or digital recorder.

(Amended 1989)

check rate. – A rate of flow usually 20 % of the capacity rate. [3.33]

checkweighing scale. – One used to verify predetermined weight within prescribed limits. [2.24]

class of grain. – Hard Red Winter Wheat as distinguished from Hard Red Spring Wheat as distinguished from Soft 

Red Winter Wheat, etc. [5.56(a), 5.56(b), 5.57]

clear interval between graduations. – The distance between adjacent edges of successive graduations in a series of

graduations. If the graduations are “staggered,” the interval shall be measured, if necessary, between a graduation and 

an extension of the adjacent graduation. (Also see “minimum clear interval.”) [1.10]

cleared. – A taximeter is “cleared” when it is inoperative with respect to all fare indication, when no indication of 

fare or extras is shown and when all parts are in those positions in which they are designed to be when the vehicle on 

which the taximeter is installed is not engaged by a passenger. [5.54]
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cold-tire pressure. – The pressure in a tire at ambient temperature. [5.53, 5.54]

commercial equipment. – See “equipment.”

(Added 2008)

computing scale. – One that indicates the money values of amounts of commodity weighed, at predetermined unit 

prices, throughout all or part of the weighing range of the scale. [2.20]

computing type or computing type device. – A device designed to indicate, in addition to weight or measure, the 

total money value of product weighed or measured, for one of a series of unit prices. [1.10]

concave curve. – A change in the angle of inclination of a belt conveyor where the center of the curve is above the 

conveyor. [2.21]

concentrated load capacity (CLC) (also referred to as Dual Tandem Axle Capacity[DTAC]). – A capacity rating of 

a vehicle or axle-load scale, specified by the manufacturer, defining the maximum load applied by a group of two 

axles with a centerline spaced four feet apart and an axle width of eight feet for which the weighbridge is designed. 

The concentrated load capacity rating is for both test and use. [2.20]

(Added 1988) (Amended 1991, 1994, and 2003)

configuration parameter. – Any adjustable or selectable parameter for a device feature that can affect the accuracy 

of a transaction or can significantly increase the potential for fraudulent use of the device and, due to its nature, needs 

to be updated only during device installation or upon replacement of a component (e.g., division value (increment), 

sensor range, and units of measurement). [2.20, 2.21, 2.24, 3.30, 3.31, 3.32, 3,34, 3.35, 3.36, 3.37, 3.38, 3.39, 5.54,

5.56(a), 5.58]

(Added 1993) (Amended 2019)

consecutive-car test train. – A train consisting of cars weighed on a reference scale, then coupled consecutively and 

run over the coupled-in-motion railway track scale under test. [2.20]

(Added 1990)

construction materials hopper scale. – A scale adapted to weighing construction materials such as sand, gravel, 

cement, and hot oil. [2.20]

contract sale. – A sale where a written agreement exists, prior to the point of sale, in which both buyer and seller have 

accepted pricing conditions of the sale. Examples include, but are not limited to: e-commerce, club sales, or prepurchase agreements. Any devices used in the determination of quantity must comply with NIST Handbook 44. [3.30, 

3.32, 3.37]

(Added 1993) (Amended 2002)

conventional scale. – If the use of conversion tables is necessary to obtain a moisture content value, the moisture 

meter indicating scale is called “conventional scale.” The values indicated by the scale are dimensionless. [5.56(b)]

conversion table. – Any table, graph, slide rule, or other external device used to determine the moisture content from 

the value indicated by the moisture meter. [5.56(b)]

convex curve. – A change in the angle of inclination of a belt conveyor where the center of the curve is below the 

conveyor. [2.21]

conveyor stringers. – Support members for the conveyor on which the scale and idlers are mounted. [2.21]

correct. – A piece of equipment is “correct” when, in addition to being accurate, it meets all applicable specification 

requirements. Equipment that fails to meet any of the requirements for correct equipment is “incorrect.” (Also see 

“accurate.”) [Appendix A]
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correction table. – Any table, graph, slide rule, or other external device used to determine the moisture content from 

the value indicated by the moisture meter when the indicated value is altered by a parameter not automatically 

corrected for in the moisture meter (for example, temperature or test weight). [5.56(b)]

counterbalance weight(s). – One intended for application near the butt of a weighbeam for zero-load balancing 

purposes. [2.20]

counterpoise weight(s). – A slotted or “hanger” weight intended for application near the tip of the weighbeam of a 

scale having a multiple greater than one. [2.20]

coupled-in-motion railroad weighing system. – A device and related installation characteristics consisting of (1) the 

associated approach trackage, (2) the scale (i.e., the weighing element, the load-receiving element, and the indicating 

element with its software), and (3) the exit trackage, which permit the weighing of railroad cars coupled in motion.

[2.20, 2.23]

(Added 1992)

crane scale. – One with a nominal capacity of 5000 pounds or more designed to weigh loads while they are suspended 

freely from an overhead, track-mounted crane. [2.20]

cryogenic liquid-measuring device. – A system including a liquid-measuring element designed to measure and 

deliver cryogenic liquids in the liquid state. [3.34]

(Amended 1986 and 2003)

cryogenic liquids. – Fluids whose normal boiling point is below 120 kelvin (− 243 °F). [3.34]

cubic foot, gas. – The amount of a cryogenic liquid in the gaseous state at a temperature of 70 °F and under a pressure 

of 14.696 lb/in2 absolute that occupies one cubic foot (1 ft3

). (See NTP.) [3.34]

D

“d,” dimension division value. – The smallest increment that the device displays for any axis and length of object in that axis.

[5.58]

d, value scale division. – See “scale division, value of (d).” [2.20, 2.22]

Dmax (maximum load of the measuring range). – Largest value of a quantity (mass) which is applied to a load cell 

during test or use. This value shall not be greater than Emax. [2.20]

(Added 2005)

Dmin (minimum load of the measuring range). – Smallest value of a quantity (mass) which is applied to a load cell 

during test or use. This value shall not be less than Emin. [2.20]

(Added 2006)

data acquisition time (DAT). – The total time an object is completely on a load-receiving element while it is being 

weighed in motion. An object is completely on a load-receiving element from the time the trailing edge of an object 

to be weighed first moves onto the load-receiving element up to the time the leading edge of the object first moves off 

the load-receiving element. This time duration is affected by the length of the load-receiving element, speed of the 

object to be weighed, and the length of the object to be weighed. [2.20]

(Added 2021)

dairy-product-test scale. – A scale used in determining the moisture content of butter and/or cheese or in determining 

the butterfat content of milk, cream, or butter. [2.20]
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decimal submultiples. – Parts obtained by successively dividing by the number 10. Thus 0.1, 0.01, 0.001, and so on 

are decimal submultiples. [1.10]

decreasing-load test. – A test for automatic-indicating scales only, wherein the performance of the scale is tested as 

the load is reduced. [2.20, 2.22]

(Amended 1987)

deficiency. – See “excess and deficiency.” [1.10]

diesel gallon equivalent (DGE). – Diesel gallon equivalent (DGE) means 6.384 pounds of compressed natural gas or 

6.059 pounds of liquefied natural gas. [3.37]

(Added 2016)

digital type. – A system of indication or recording of the selector type or one that advances intermittently in which 

all values are presented digitally, or in numbers. In a digital indicating or recording element, or in digital 

representation, there are no graduations. [1.10]

dimensional offset. – The effect of eliminating the conveyance material on a measurement made by a multiple 

dimension measuring device resulting in only the object intended to be measured being measured. [5.58.]

(Added 2021)

dimensional weight (or dim, weight). – A value computed by dividing the object’s volume by a conversion factor; 

it may be used for the calculation of charges when the value is greater than the actual weight. [5.58]

(Added 2004)

direct sale. – A sale in which both parties in the transaction are present when the quantity is being determined. An 

unattended automated or customer-operated weighing or measuring system is considered to represent the 

device/business owner in transactions involving an unattended device. [1.10]

(Amended 1993)

discharge hose. – A flexible hose connected to the discharge outlet of a measuring device or its discharge line. [3.30, 

3.31, 3.32, 3.34, 3.37, 3.38, 3.39]

(Added 1987) (Amended 2019)

discharge line. – A rigid pipe connected to the outlet of a measuring device. [3.30, 3.31, 3.32, 3.34, 3.37, 3.39]

(Added 1987) (Amended 2019)

discrimination (of an automatic-indicating scale). – The value of the test load on the load-receiving element of the 

scale that will produce a specified minimum change of the indicated or recorded value on the scale. [2.20, 2.22]

dispenser. – See motor-fuel device. [3.30, 3.37]

distributed-car test train. – A train consisting of cars weighed first on a reference scale, cars coupled consecutively 

in groups at different locations within the train, then run over the coupled-in-motion railway track scale under test. 

The groups are typically placed at the front, middle, and rear of the train. [2.20]

(Added 1990)

dry hose. – A discharge hose intended to be completely drained at the end of each delivery of product. (Also see

“dry-hose type.”) [3.30, 3.31]

(Amended 2002)

dry-hose type. – A type of device in which it is intended that the discharge hose be completely drained following the 

mechanical operations involved in each delivery. (Also see “dry hose.”) [3.30, 3.31, 3.34, 3.35]
Appendix D – Definitions Handbook 44 – 2022

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dynamic monorail weighing system. – A weighing system which employs hardware or software to compensate for 

dynamic effects from the load or the system that do not exist in static weighing, in order to provide a stable indication. 

Dynamic factors may include shock or impact loading, system vibrations, oscillations, etc., and can occur even when 

the load is not moving across the load-receiving element. [2.20]

(Added 1999)

E

e, value of verification scale division. – See “verification scale division, value of (e).” [2.20]

Emax (maximum capacity). – Largest value of a quantity (mass) which may be applied to a load cell without exceeding 

the mpe. [2.20]

(Added 2005)

Emin (minimum dead load). – Smallest value of a quantity (mass) which may be applied to a load cell during test or 

use without exceeding the mpe. [2.20]

(Added 2006)

emin (minimum verification scale division). – The smallest scale division for which a weighing element complies 

with the applicable requirements. [2.20, 2.21, 2.24]

(Added 1997)

electronic link. – An electronic connection between the weighing/load-receiving or other sensing element and 

indicating element where one recognizes the other and neither can be replaced without calibration. [2.20]

(Added 2001)

element. – A portion of a weighing or measuring device or system which performs a specific function and can be 

separated, evaluated separately, and is subject to specified full or partial error limits.

(Added 2002)

equal-arm scale. – A scale having only a single lever with equal arms (that is, with a multiple of one), equipped with 

two similar or dissimilar load-receiving elements (pan, plate, platter, scoop, or the like), one intended to receive 

material being weighed and the other intended to receive weights. There may or may not be a weighbeam. [2.20]

equipment, commercial. – Weights, measures, and weighing and measuring devices, instruments, elements, and 

systems or portion thereof, used or employed in establishing the measurement or in computing any basic charge or 

payment for services rendered on the basis of weight or measure. As used in this definition, measurement includes 

the determination of size, quantity, value, extent, area, composition (limited to meat and poultry), constituent value 

(for grain), or measurement of quantities, things, produce, or articles for distribution or consumption, purchased, 

offered, or submitted for sale, hire, or award. [1.10, 2.20, 2.21, 2.22, 2.24, 3.30, 3.31, 3.32, 3.33, 3.34, 3.35, 3.36, 3.37,

3.38, 3.39, 4.40, 5.51, 5.56.(a), 5.56.(b), 5.57, 5.58, 5.59]

(Added 2008) (Amended 2019)

event counter. – A non-resettable counter that increments once each time the mode that permits changes to sealable 

parameters is entered and one or more changes are made to sealable calibration or configuration parameters of a 

device. [2.20, 2.21, 2.24, 3.30, 3.31, 3.32, 3.34, 3.35, 3.36, 3.37, 3.38, 3.39, 5.54, 5.56(a), 5.56(b), 5.57, 5.58]

(Added 1993) (Amended 2019)

event logger. – A form of audit trail containing a series of records where each record contains the number from the event 

counter corresponding to the change to a sealable parameter, the identification of the parameter that was changed, the time 

and date when the parameter was changed, and the new value of the parameter. [2.20, 2.21, 2.24, 3.30, 3.31, 3.32, 3.34, 3.35, 

3.36, 3.37, 3.38, 3.39, 5.54, 5.56(a), 5.56(b), 5.57, 5.58]

(Added 1993) (Amended 2019)
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excess and deficiency. – When an instrument or device is of such a character that it has a value of its own that can be 

determined, its error is said to be “in excess” or “in deficiency,” depending upon whether its actual value is, 

respectively, greater or less than its nominal value. (Also see “nominal.”) Examples of instruments having errors “in 

excess” are: a linear measure that is too long; a liquid measure that is too large; and a weight that is “heavy.” Examples 

of instruments having errors “in deficiency” are: a lubricating-oil bottle that is too small; a vehicle tank compartment 

that is too small; and a weight that is “light.” [1.10]

extras. – Charges to be paid by a passenger in addition to the fare, including any charge at a flat rate for the 

transportation of passengers in excess of a stated number and any charge for the transportation of baggage. [5.54]

F

face. – That side of a taximeter on which passenger charges are indicated. [5.54]

face. – That portion of a computing-type pump or dispenser which displays the actual computation of price per unit, 

delivered quantity, and total sale price. In the case of some electronic displays, this may not be an integral part of the 

pump or dispenser. [3.30]

(Added 1987)

fare. – That portion of the charge for the hire of a vehicle that is automatically calculated by a taximeter through the 

operation of the distance and/or time mechanism. [5.54]

farm milk tank. – A unit for measuring milk or other fluid dairy product, comprising a combination of (1) a stationary 

or portable tank, whether or not equipped with means for cooling its contents, (2) means for reading the level of liquid 

in the tank, such as a removable gauge rod or a surface gauge, and (3) a chart for converting level-of-liquid readings 

to volume; or such a unit in which readings are made on a gauge rod or surface gauge directly in terms of volume. 

Each compartment of a subdivided tank shall, for purposes of this code, be construed to be a “farm milk tank.” [4.43]

feeding mechanism. – The means for depositing material to be weighed on the belt conveyor. [2.21]

ft3

/h. – Cubic feet per hour. [3.33]

fifth wheel. – A commercially-available distance-measuring device which, after calibration, is recommended for use 

as a field transfer standard for testing the accuracy of taximeters and odometers on rented vehicles. [5.53, 5.54]

fifth-wheel test. – A distance test similar to a road test, except that the distance traveled by the vehicle under test is 

determined by a mechanism known as a “fifth wheel” that is attached to the vehicle and that independently measures 

and indicates the distance. [5.53, 5.54]

flat rate. – A rate selection that when applied results in the indication of a fixed (non-incrementing) amount for 

passenger charges. This rate shall be included on the statement of established rates that is required to be posted in the 

vehicle. [5.54.]

(Added 2016)

fractional bar. – A weighbeam bar of relatively small capacity for obtaining indications intermediate between notches 

or graduations on a main or tare bar. [2.20]

G

gasoline gallon equivalent (GGE). – Gasoline gallon equivalent (GGE) means 5.660 pounds of compressed natural 

gas. [3.37]

(Added 1994) (Amended 2016)

gauge pressure. – The difference between the pressure at the meter and the atmospheric pressure (psi). [3.33]
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gauge rod. – A graduated, “dip-stick” type of measuring rod designed to be partially immersed in the liquid and to be 

read at the point where the liquid surface crosses the rod. [4.42]

gauging. – The process of determining and assigning volumetric values to specific graduations on the gauge or gauge 

rod that serve as the basis for the tank volume chart. [4.42]

graduated interval. – The distance from the center of one graduation to the center of the next graduation in a series 

of graduations. (Also see “value of minimum graduated interval.”) [1.10]

graduation. – A defining line or one of the lines defining the subdivisions of a graduated series. The term includes 

such special forms as raised or indented or scored reference “lines” and special characters such as dots. (Also see 

“main graduation” and “subordinate graduation.”) [1.10]

grain class. – Different grains within the same grain type. For example, there are six classes for the grain type 

“wheat:” Durum Wheat, Hard Red Spring Wheat, Hard Red Winter Wheat, Soft Red Winter Wheat, Hard White 

Wheat, and Soft White Wheat. [5.56(a), 5.57]

(Added 2007)

grain hopper scale. – One adapted to the weighing of individual loads of varying amounts of grain. [2.20]

grain moisture meter. – Any device indicating either directly or through conversion tables and/or correction tables 

the moisture content of cereal grains and oil seeds. Also termed “moisture meter.” [5.56(a), 5.56(b)]

grain sample. – That portion of grain or seed taken from a bulk quantity of grain or seed to be bought or sold and 

used to determine the moisture content of the bulk. [5.56(a), 5.56(b)]

grain-test scale. – A scale adapted to weighing grain samples used in determining moisture content, dockage, weight 

per unit volume, etc. [2.20]

grain type. – See “kind of grain.” [5.56(a), 5.57]

(Added 2007)

gravity discharge. – A type of device designed for discharge by gravity. [3.30, 3.31]

H

head pulley. – The pulley at the discharge end of the belt conveyor. The power drive to drive the belt is generally 

applied to the head pulley. [2.21]

hexahedron. – A geometric solid (i.e., box) with six rectangular or square plane surfaces. [5.58]

(Added 2008)

hired. – A taximeter is “hired” when it is operative with respect to all applicable indications of fare or extras. The 

indications of fare include time and distance where applicable unless qualified by another indication of “Time Not 

Recording” or an equivalent expression. [5.54]

hopper scale. – A scale designed for weighing bulk commodities whose load-receiving element is a tank, box, or 

hopper mounted on a weighing element. (Also see “automatic hopper scale,” “grain hopper scale,” and “construction 

materials hopper scale.”) [2.20]

I

idlers or idler rollers. – Freely turning cylinders mounted on a frame to support the conveyor belt. For a flat belt, 

the idlers consist of one or more horizontal cylinders transverse to the direction of belt travel. For a troughed belt, the 
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idlers consist of one or more horizontal cylinders and one or more cylinders at an angle to the horizontal to lift the 

sides of the belt to form a trough. [2.21]

idler space. – The center-to-center distance between idler rollers measured parallel to the belt. [2.21]

increasing-load test. – The normal basic performance test for a scale in which observations are made as increments 

of test load are successively added to the load-receiving element of the scale. [2.20, 2.22]

increment. – The value of the smallest change in value that can be indicated or recorded by a digital device in normal 

operation. [1.10]

index of an indicator. – The particular portion of an indicator that is directly utilized in making a reading. [1.10]

indicating element. – An element incorporated in a weighing or measuring device by means of which its performance 

relative to quantity or money value is “read” from the device itself as, for example, an index-and-graduated-scale 

combination, a weighbeam-and-poise combination, a digital indicator, and the like. (Also see “primary indicating or 

recording element.”) [1.10]

indicator, balance. – See “balance indicator.” [2.20]

initial distance or time interval. – The interval corresponding to the initial money drop. [5.54]

initial zero-setting mechanism. – See “initial zero-setting mechanism” under “zero-setting mechanism.” [2.20]

(Added 1990)

in-service light indicator. – A light used to indicate that a timing device is in operation. [5.55]

integrator. – A device used with a belt-conveyor scale that combines conveyor belt load (e.g., lb/ft) and belt travel 

(e.g., feet) to produce a total weight of material passing over the belt-conveyor scale. An integrator may be a separate, 

detached mechanism or may be a component within a totalizing device. (Also see “master weight totalizer.”) [2.21]

(Added 2013)

interval, clear, between graduations. – See “clear interval between graduations.” [1.10]

interval, graduated. – See “graduated interval.” [1.10]

irregularly-shaped object. – Any object that is not a hexahedron shape. [5.58]

(Added 2008)

J

jewelers’ scale. – One adapted to weighing gems and precious metals. [2.20]

K

kind of grain. – Corn as distinguished from soybeans as distinguished from wheat, etc. [5.56(a), 5.56(b)]

L

label. – A printed ticket, to be attached to a package, produced by a printer that is a part of a prepackaging scale or 

that is an auxiliary device. [2.20]

large-delivery device. – Devices used primarily for single deliveries greater than 200 gallons, 2000 pounds, 

20 000 cubic feet, 2000 liters, or 2000 kilograms. [3.34, 3.38]
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laundry-drier timer. – A timer used in conjunction with a coin-operated device to measure the period of time that a 

laundry drier is in operation. [5.55]

liquefied petroleum gas. – A petroleum product composed predominantly of any of the following hydrocarbons or 

mixtures thereof: propane, propylene, butanes (normal butane or isobutane), and butylenes. [3.31, 3.32, 3.33, 3.34, 

3.37]

liquefied petroleum gas liquid-measuring device. – A system including a mechanism or machine of the meter type 

designed to measure and deliver liquefied petroleum gas in the liquid state by a definite quantity, whether installed in 

a permanent location or mounted on a vehicle. Means may or may not be provided to indicate automatically, for one 

of a series of unit prices, the total money value of the liquid measured. [3.33]

(Amended 1987)

liquefied petroleum gas vapor-measuring device. – A system including a mechanism or device of the meter type, 

equipped with a totalizing index, designed to measure and deliver liquefied petroleum gas in the vapor state by definite 

volumes, and generally installed in a permanent location. The meters are similar in construction and operation to the 

conventional natural- and manufactured-gas meters. [3.33]

liquid fuel. – Any liquid used for fuel purposes, that is, as a fuel, including motor-fuel. [3.30, 3.31]

liquid-fuel device. – A device designed for the measurement and delivery of liquid fuels. [3.30]

liquid-measuring device. – A mechanism or machine designed to measure and deliver liquid by definite volume. 

Means may or may not be provided to indicate automatically, for one of a series of unit prices, the total money value 

of the liquid measured, or to make deliveries corresponding to specific money values at a definite unit price. [3.30]

liquid volume correction factor. – A correction factor used to adjust the liquid volume of a cryogenic product at the 

time of measurement to the liquid volume at NBP. [3.34]

livestock scale. – A scale equipped with stock racks and gates and adapted to weighing livestock standing on the scale 

platform. [2.20]

(Amended 1989)

load cell. – A device, whether electric, hydraulic, or pneumatic, that produces a signal (change in output) proportional 

to the load applied. [2.20, 2.21, 2.23]

load cell verification interval (v). – The load cell interval, expressed in units of mass, used in the test of the load cell 

for accuracy classification. [2.20, 2.21]

(Added 1996)

loading point. – A location on a conveyor where the material is received by the belt. The location of the discharge 

from a hopper, chute, or pre-feed device used to supply material to a conveyor. [2.21]

(Amended 2013)

load-receiving element. – That element of a scale that is designed to receive the load to be weighed; for example, 

platform, deck, rail, hopper, platter, plate, scoop. [2.20, 2.21, 2.23]

location services. – Any of the various technologies used to determine the geographical location of a receiving unit 

in or physically attached to a vehicle. These technologies may include but are not limited to: global positioning 

services; cellular networks; or wi-fi networks. [5.54]

(Added 2017)

low-flame test. – A test simulating extremely low-flow rates such as caused by pilot lights. [3.33]

lubricant device. – A device designed for the measurement and delivery of liquid lubricants, including, but not limited 

to, heavy gear lubricants and automatic transmission fluids (automotive). [3.30]
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M

m3/h. – Cubic meters per hour. [3.33]

main bar. – A principal weighbeam bar, usually of relatively large capacity as compared with other bars of the same 

weighbeam. (On an automatic-indicating scale equipped with a weighbeam, the main weighbeam bar is frequently

called the “capacity bar.”) [2.20]

main graduation. – A graduation defining the primary or principal subdivisions of a graduated series. (Also see

“graduation.”) [1.10]

main-weighbeam elements. – The combination of a main bar and its fractional bar, or a main bar alone if no fractional 

bar is associated with it. [2.20]

manual zero-setting mechanism. – See “manual zero-setting mechanism” under “zero-setting mechanism.” [2.20]

manufactured device. – Any commercial weighing or measuring device shipped as new from the original equipment 

manufacturer. [1.10]

(Amended 2001)

mass flow meter. – A device that measures the mass of a product flowing through the system. The mass measurement 

may be determined directly from the effects of mass on the sensing unit or may be inferred by measuring the properties 

of the product, such as the volume, density, temperature, or pressure, and displaying the quantity in mass units. [3.37]

master meter test method. – A method of testing milk tanks that utilizes an approved master meter system for 

measuring test liquid removed from or introduced into the tank. [4.42]

master weight totalizer. – A primary indicating element used with a belt-conveyor scale that incorporates the function 

of an integrator to indicate the totalized weight of material passed over the scale. (Also see “integrator.”) [2.21]

(Amended 2013)

material test. – The test of a belt-conveyor scale using material (preferably that for which the device is normally 

used) that has been weighed to an accuracy of 0.1 %. [2.21]

(Amended 1989)

maximum capacity. – The largest load that may be accurately weighed. [2.20, 2.24]

(Added 1999)

maximum cargo load. – The maximum cargo load for trucks is the difference between the manufacturer’s rated gross 

vehicle weight and the actual weight of the vehicle having no cargo load. [5.53]

measurement field. – A region of space or the measurement pattern produced by the measuring instrument in which 

objects are placed or passed through, either singly or in groups, when being measured by a single device. [5.58]

measuring element. – That portion of a complete multiple dimension measuring device that does not include the 

indicating element. [5.58]

meter register. – An observation index for the cumulative reading of the gas flow through the meter. In addition,

there are one or two proving circles in which one revolution of the test hand represents 1⁄2, 1, 2, 5, or 10 cubic feet, or 

0.025, 0.05, 0.1, 0.2, or 0.25 cubic meter, depending on meter size. If two proving circles are present, the circle 

representing the smallest volume per revolution is referred to as the “leak-test circle.” [3.33]
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metrological integrity (of a device). – The design, features, operation, installation, or use of a device that facilitates 

(1) the accuracy and validity of a measurement or transaction, (2) compliance of the device with weights and measures 

requirements, or (3) the suitability of the device for a given application. [1.10, 2.20]

(Added 1993)

minimum capacity. – The smallest load that may be accurately weighed. The weighing results may be subject to 

excessive error if used below this value. [2.20, 2.24]

(Added 1999)

minimum clear interval. – The shortest distance between adjacent graduations when the graduations are not parallel. 

(Also see “clear interval.”) [3.30, 3.31, 3.32, 3.33, 3.34, 3.35, 3.36, 3.38, 5.50, 5.51, 5.56(b)]

minimum delivery. – The least amount of weight that is to be delivered as a single weighment by a belt-conveyor 

scale system in normal use. [2.21]

minimum load cell verification interval. – See vmin

minimum measured quantity (MMQ). – The smallest quantity delivered for which the measurement is to within the 

applicable tolerances for that system. [3.37, 3.39]

(Added 2019)

minimum tolerance. – Minimum tolerances are the smallest tolerance values that can be applied to a scale. Minimum 

tolerances are determined on the basis of the value of the minimum graduated interval or the nominal or reading face 

capacity of the scale. (Also see definition for basic tolerances.) [2.20, 2.22, 2.24]

minimum totalized load. – The least amount of weight for which the scale is considered to be performing accurately.

[2.21]

moisture content (wet basis). – The mass of water in a grain or seed sample (determined by the reference method) 

divided by the mass of the grain or seed sample expressed as a percentage (%). [5.56(a), 5.56(b)]

money drop. – An increment of fare indication. The “initial money drop” is the first increment of fare indication 

following activation of the taximeter. [5.54]

money-operated type. – A device designed to be released for service by the insertion of money, or to be actuated by 

the insertion of money to make deliveries of product. [1.10]

motor-fuel. – Liquid used as fuel for internal-combustion engines. [3.30]

motor-fuel device or motor-fuel dispenser or retail motor-fuel device. – A device designed for the measurement 

and delivery of liquids used as fuel for internal-combustion engines. The term “motor-fuel dispenser” means the same 

as “motor-fuel device”; the term “retail motor-fuel device” applies to a unique category of device. (Also see definition 

of “retail device.”) [3.30, 3.32, 3.37]

multi-class. – A description of a grouping of grain classes, from the same grain type, in one calibration. A multi-class 

grain calibration may include (1) all the classes of a grain type (all-class calibration), or (2) some of the classes of a 

grain type within the calibration. [5.56(a), 5.57.]

(Added 2007)

multi-interval scale. – A scale having one weighing range which is divided into partial weighing ranges (segments), 

each with different scale intervals, with each partial weighing range (segment) determined automatically according to 

the load applied, both on increasing and decreasing loads. [2.20]

(Added 1995)
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multi-jet water meter. – A water meter in which the moving element takes the form of a multiblade rotor mounted 

on a vertical spindle within a cylindrical measuring chamber. The liquid enters the measuring chamber through several 

tangential orifices around the circumference and leaves the measuring chamber through another set of tangential 

orifices placed at a different level in the measuring chamber. These meters register by recording the revolutions of a 

rotor set in motion by the force of flowing water striking the blades. [3.36]

(Added 2003)

multiple. – An integral multiple; that is, a result obtained by multiplying by a whole number. (Also see “multiple of 

a scale.”) [1.10]

multiple cell application load cell. – A load cell intended for use in a weighing system which incorporates more than 

one load cell. A multiple cell application load cell is designated with the letter “M” or the term “Multiple.” (Also see 

“single cell application load cell.”) [2.20]

(Added 1999)

multiple range scale. – A scale having two or more weighing ranges with different maximum capacities and different 

scale intervals for the same load receptor, each range extending from zero to its maximum capacity. [2.20]

(Added 1995)

multiple of a scale. – In general, the multiplying power of the entire system of levers or other basic weighing elements. 

(On a beam scale, the multiple of the scale is the number of pounds on the load-receiving element that will be 

counterpoised by one pound applied to the tip pivot of the weighbeam.) [2.20]

multi-revolution scale. – An automatic-indicating scale having a nominal capacity that is a multiple of the 

reading-face capacity and that is achieved by more than one complete revolution of the indicator. [2.20]

multiple-tariff taximeter. – One that may be set to calculate fares at any one of two or more rates. [5.54]

N

NBP. – Normal Boiling Point of a cryogenic liquid at 14.696 lb/in2 absolute. [3.34]

NTP. – Normal Temperature and Pressure of a cryogen at a temperature of 21 °C (70 °F) and a pressure of 

101.325 kPa (14.696 lb/in2 absolute). [3.34]

NTP density and volume correction factor. – A correction factor used to adjust the liquid volume of a cryogenic 

product at the time of measurement to the gas equivalent at NTP. [3.34]

natural gas. – A gaseous fuel, composed primarily of methane, that is suitable for compression and dispensing into a 

fuel storage container(s) for use as an engine fuel. [3.37]

(Added 1994)

negotiated rate. – A rate selection that, when applied, results in a fixed (non-incrementing) amount for passenger 

charges and is based on a value that has been agreed upon by the operator and passenger. [5.54]

(Added 2016)

nmax (maximum number of scale divisions). – The maximum number of scale divisions for which a main element or 

load cell complies with the applicable requirements. The maximum number of scale divisions permitted for an 

installation is limited to the lowest nmax marked on the scale indicating element, weighing element, or load cell. [2.20, 

2.21, 2.24]

(Added 1997)
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no-load reference value. – A positive weight value indication with no load in the load-receiving element (hopper) of 

the scale. (Used with automatic bulk-weighing systems and certain single-draft, manually-operated receiving hopper 

scales installed below grade and used to receive grain.) [2.20]

nominal. – Refers to “intended” or “named” or “stated,” as opposed to “actual.” For example, the “nominal” value of 

something is the value that it is supposed or intended to have, the value that it is claimed or stated to have, or the value by 

which it is commonly known. Thus, “1-pound weight,” “1-gallon measure,” “1-yard indication,” and “500-pound scale” 

are statements of nominal values; corresponding actual values may be greater or lesser. (Also see nominal capacity of a 

scale.) [1.10]

nominal capacity. – The nominal capacity of a scale is (a) the largest weight indication that can be obtained by the 

use of all of the reading or recording elements in combination, including the amount represented by any removable 

weights furnished or ordinarily furnished with the scale, but excluding the amount represented by any extra removable 

weights not ordinarily furnished with the scale, and excluding also the capacity of any auxiliary weighing attachment 

not contemplated by the original design of the scale, and excluding any fractional bar with a capacity less than 21⁄2 % 

of the sum of the capacities of the remaining reading elements, or (b) the capacity marked on the scale by the 

manufacturer, whichever is less. (Also see “nominal capacity, batching scale”; “nominal capacity, hopper scale.”)

[2.20]

nominal capacity, batching scale. – The nominal capacity of a batching scale is the capacity as marked on the scale 

by the scale manufacturer, or the sum of the products of the volume of each of the individual hoppers, in terms of 

cubic feet, times the weight per cubic foot of the heaviest material weighed in each hopper, whichever is less. [2.20]

nominal capacity, hopper scale. – The nominal capacity of a hopper scale is the capacity as marked on the scale by 

the scale manufacturer, or the product of the volume of the hopper in bushels or cubic feet times the maximum weight 

per bushel or cubic foot, as the case may be, of the commodity normally weighed, whichever is less. [2.20]

non-automatic checkweigher. – A weighing instrument that requires the intervention of an operator during the weighing 

process, used to subdivide items of different weights into one or more subgroups, such as identifying packages that have 

acceptable or unacceptable fill levels according to the value of the difference between their weight and a pre-determined set 

point. [2.24]

Notes: Determining the weighing result includes any intelligent action of the operator that affects the result, such 

as deciding and taking an action when an indication is stable or adjusting the weight of the weighed load.

Deciding the weighing result is acceptable means making a decision regarding the acceptance of each weighing 

result on observing the indication or releasing a print-out. The weighing process allows the operator to take an 

action which influences the weighing result in the case where the weighing result is not acceptable.

(Added 2004)

non-automatic weighing instrument. – A weighing instrument or system that requires the intervention of an operator 

during the weighing process to determine the weighing result or to decide that it is acceptable. [2.20, 2.24]

Notes: Determining the weighing result includes any intelligent action of the operator that affects the result, such 

as deciding and taking an action when an indication is stable or adjusting the weight of the weighed load.

Deciding the weighing result is acceptable means making a decision regarding the acceptance of each weighing 

result on observing the indication or releasing a print-out. The weighing process allows the operator to take an 

action which influences the weighing result in the case where the weighing result is not acceptable.

(Added 2004) (Amended 2005)

non-resettable totalizer. – An element interfaced with the measuring or weighing element that indicates the 

cumulative registration of the measured quantity with no means to return to zero. [3.30, 3.37, 3.39]

(Added 2019)
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nonretroactive. – “Nonretroactive” requirements are enforceable after the effective date for:

1. devices manufactured within a state after the effective date;

2. both new and used devices brought into a state after the effective date; and

3. devices used in noncommercial applications which are placed into commercial use after the effective date.

Nonretroactive requirements are not enforceable with respect to devices that are in commercial service in the state as 

of the effective date or to new equipment in the stock of a manufacturer or a dealer in the state as of the effective date. 

(Nonretroactive requirements are printed in italic type.) [1.10]

(Amended 1989)

nose-iron. – A slide-mounted, manually-adjustable pivot assembly for changing the multiple of a lever. [2.20]

notes. – A section included in each of a number of codes, containing instructions, pertinent directives, and other 

specific information pertaining to the testing of devices. Notes are primarily directed to weights and measures 

officials.

O

odometer. – A device that automatically indicates the total distance traveled by a vehicle. For the purpose of this 

code, this definition includes hub odometers, cable-driven odometers, and the distance-indicating or odometer portions 

of “speedometer” assemblies for automotive vehicles. [5.53]

official grain samples. – Grain or seed used by the official as the official transfer standard from the reference standard 

method to test the accuracy and precision of grain moisture meters. [5.56(a), 5.56(b)]

official with statutory authority. – The representative of the jurisdiction(s) responsible for certifying the accuracy 

of the device. [2.20, 2.21, 2.22]

(Added 1991)

operating tire pressure. – The pressure in a tire immediately after a vehicle has been driven for at least 5 miles or 

8 kilometers. [5.53, 5.54]

over-and-under indicator. – An automatic-indicating element incorporated in or attached to a scale and comprising 

an indicator and a graduated scale with a central or intermediate “zero” graduation and a limited range of weight 

graduations on either side of the zero graduation, for indicating weights greater than and less than the predetermined 

values for which other elements of the scale may be set. (A scale having an over-and-under indicator is classed as an 

automatic-indicating scale.) [2.20]

overregistration and underregistration. – When an instrument or device is of such a character that it indicates or 

records values as a result of its operation, its error is said to be in the direction of overregistration or underregistration, 

depending upon whether the indications are, respectively, greater or less than they should be. Examples of devices 

having errors of “overregistration” are: a fabric-measuring device that indicates more than the true length of material 

passed through it; and a liquid-measuring device that indicates more than the true amount of the liquid delivered by 

the device. Examples of devices having errors of “underregistration” are: a meter that indicates less than the true 

amount of product that it delivers; and a weighing scale that indicates or records less than the true weight of the applied 

load. [1.10]
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P

parallax. – The apparent displacement, or apparent difference in height or width, of a graduation or other object with 

respect to a fixed reference, as viewed from different points. [1.10]

parking meter. – A coin-operated device for measuring parking time for vehicles. [5.55]

passenger vehicles. – Vehicles such as automobiles, recreational vehicles, limousines, ambulances, and hearses.

[5.53]

performance requirements. – Performance requirements include all tolerance requirements and, in the case of 

nonautomatic-indicating scales, sensitivity requirements (SR). (Also see definitions for “tolerance” and “sensitivity 

requirement.”) [1.10]

point-based railroad weighing systems. – An in-motion-railroad weighing system designed to weigh wheel(s) of a 

railway car when centered on the load sensor within a weighing zone typically of 2 inches or less. The weight of the 

wheels are added to obtain the total weight of the cars and train which are used for any transaction. [2.20]

(Added 2021)

point-of-sale system. – An assembly of elements including a weighing or measuring element, an indicating element, 

and a recording element (and may also be equipped with a “scanner”) used to complete a direct sales transaction. The 

system components, when operated together, must be capable of the following:

1. determining the weight or measure of a product or service offered;

2. calculating a charge for the product or service based on the weight or measure and an established price/rate 

structure;

3. determining a total cost that includes all associated charges involved with the transaction; and

4. providing a sales receipt.

[2.20, 3.30, 3.32, 3.37, 3.39]

(Added 1986) (Amended 1997, 2015, and 2019)

poise. – A movable weight mounted upon or suspended from a weighbeam bar and used in combination with 

graduations, and frequently with notches, on the bar to indicate weight values. (A suspended poise is commonly called 

a “hanging poise.”) [2.20]

postal scale. – A scale (usually a computing scale) designed for use to determine shipping weight or delivery charges 

for letters or parcels delivered by the U.S. Postal Service or private shipping companies. A weight classifier may be 

used as a postal scale. [2.20]

(Added 1987)

prepackaging scale. – A computing scale specially designed for putting up packages of random weights in advance 

of sale. [2.20]

prescription scale. – A scale or balance adapted to weighing the ingredients of medicinal and other formulas 

prescribed by physicians and others and used or intended to be used in the ordinary trade of pharmacists. [2.20]

pressure type (device). – A type of device designed for operation with the liquid under artificially produced pressure.

[3.30, 3.31]

primary indicating or recording elements. – The term “primary” is applied to those principal indicating (visual) 

elements and recording elements that are designed to, or may, be used by the operator in the normal commercial use 
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of a device. The term “primary” is applied to any element or elements that may be the determining factor in arriving 

at the sale representation when the device is used commercially. (Examples of primary elements are the visual 

indicators for meters or scales not equipped with ticket printers or other recording elements and both the visual 

indicators and the ticket printers or other recording elements for meters or scales so equipped.) The term “primary” 

is not applied to such auxiliary elements as, for example, the totalizing register or predetermined-stop mechanism on 

a meter or the means for producing a running record of successive weighing operations, these elements being 

supplementary to those that are the determining factors in sales representations of individual deliveries or weights. 

(Also see “indicating element” and “recording element.”) [1.10]

prover method. – A method of testing milk tanks that utilizes approved volumetric prover(s) for measuring the test 

liquid removed from or introduced into the tank. [4.42]

prover oil. – A light oil of low vapor pressure used as a sealing medium in bell provers, cubic-foot bottles, and portable 

cubic-foot standards. [3.33]

proving indicator. – The test hand or pointer of the proving or leak-test circle on the meter register or index. [3.33, 

3.36.]

R

“r” factor. – A computation for determining the suitability of a vehicle scale for weighing vehicles with varying axle 

configurations. The factor was derived by dividing the weights in FHWA Federal Highway Bridge Gross Weight 

Table B by 34 000 lbs. (The resultant factors are contained in Table UR.3.2.1.) [2.20]

radio frequency interference (RFI). – Radio frequency interference is a type of electrical disturbance that, when 

introduced into electronic and electrical circuits, may cause deviations from the normally expected performance. [1.10]

random error(s). – The sample standard deviation of the error (indicated values) for a number of consecutive 

automatic weighings of a load, or loads, passed over the load receptor, shall be expressed mathematically as:

( ) ( )

2 2 2 1

1

1

1

 or i X X

n n

X X i i n s s −

− −

     

∑ = −= ∑ ∑

where: X = error of a load indication

n = the number of loads

[2.24]

ranges, weight. – See “weight ranges.” [2.20]

rated capacity. – The rate of flow in cubic meters per hour of a hydrocarbon gas vapor-measuring device as 

recommended by the manufacturer. This rate of flow should cause a pressure drop across the meter not exceeding 

1⁄2-inch water column. [3.33]

rated scale capacity. – That value representing the weight that can be delivered by the device in one hour. [2.21]

ratio test. – A test to determine the accuracy with which the actual multiple of a scale agrees with its designed multiple. 

This test is used for scales employing counterpoise weights and is made with standard test weights substituted in all 

cases for the weights commercially used on the scale. (It is appropriate to use this test for some scales not employing 

counterpoise weights.) [2.20]

reading face. – That portion of an automatic-indicating weighing or measuring device that gives a visible indication 

of the quantity weighed or measured. A reading face may include an indicator and a series of graduations or may 

present values digitally, and may also provide money-value indications. [1.10, 2.20]

(Amended 2005)
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reading-face capacity. – The largest value that may be indicated on the reading face, exclusive of the application or 

addition of any supplemental or accessory elements. [1.10]

recorded representation. – The printed, embossed, or other representation that is recorded as a quantity by a weighing 

or measuring device. [1.10]

recording element. – An element incorporated in a weighing or measuring device by means of which its performance 

relative to quantity or money value is permanently recorded on a tape, ticket, card, or the like, in the form of a printed, 

stamped, punched, or perforated representation. [1.10, 2.21]

recording scale. – One on which the weights of applied loads may be permanently recorded on a tape, ticket, card, or 

the like in the form of a printed, stamped, punched, or perforated representation. [2.20]

reference weight car. – A railcar that has been statically weighed for temporary use as a mass standard over a short 

period of time, typically the time required to test one scale.

Note: A test weight car that is representative of the types of cars typically weighed on the scale under test may be 

used wherever reference weight cars are specified. [2.20]

(Added 1991) (Amended 2012)

reference vehicle. – A vehicle with an associated load, including the driver, that has been statically weighed for 

temporary use as a field standard, typically the time required to test on weigh-in-motion vehicle scale. [2.20]

(Added 2021)

remanufactured device. – A device that is disassembled, checked for wear, parts replaced or fixed, reassembled and 

made to operate like a new device of the same type. [1.10]

(Added 2001)

remanufactured element. – An element that is disassembled, checked for wear, parts replaced or fixed, reassembled 

and made to operate like a new element of the same type. [1.10]

(Added 2001)

remote configuration capability. – The ability to adjust a weighing or measuring device or change its sealable 

parameters from or through some other device that is not itself necessary to the operation of the weighing or measuring 

device or is not a permanent part of that device. [2.20, 2.21, 2.24, 3.30, 3.31, 3.32, 3.34, 3.35, 3.36, 3.37, 3.38, 3.39,

5.54, 5.56(a), 5.58]

(Added 1993) (Amended 2019)

repaired device. – A device to which work is performed that brings the device back into proper operating condition.

[1.10]

(Added 2001)

repaired element. – An element to which work is performed that brings the element back into proper operating 

condition. [1.10]

(Added 2001)

retail device. – A measuring device primarily used to measure product for the purpose of sale to the end user. [3.30, 

3.32, 3.37, 3.39]

(Amended 1987, 2004, and 2019)

retroactive. – “Retroactive” requirements are enforceable with respect to all equipment. Retroactive requirements 

are printed herein in upright roman type. (Also see “nonretroactive.”) [1.10]
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road test. – A distance test, over a measured course, of a complete taximeter assembly when installed on a vehicle, 

the mechanism being actuated as a result of vehicle travel. [5.53, 5.54]

rolling circumference. – The rolling circumference is the straight-line distance traveled per revolution of the wheel 

(or wheels) that actuates the taximeter or odometer. If more than one wheel actuates the taximeter or odometer, the 

rolling circumference is the average distance traveled per revolution of the actuating wheels. [5.53, 5.54]

S

scale. – See specific type of scale. [2.20]

scale area, belt-conveyor. – See belt-conveyor scale systems area. [2.21]

(Added 2001)

scale division, number of (n). – Quotient of the capacity divided by the value of the verification scale division. [2.20]

e

Capacity n = 

scale division, value of (d). – The value of the scale division, expressed in units of mass, is the smallest subdivision 

of the scale for analog indication or the difference between two consecutively indicated or printed values for digital 

indication or printing. (Also see “verification scale division.”) [2.20, 2.22]

scale section. – A part of a vehicle, axle-load, livestock, or railway track scale consisting of two main load supports, 

usually transverse to the direction in which the load is applied. [2.20]

seal. – See “approval seal,” “security seal.” [1.10]

section capacity. – The section capacity of a scale is the maximum live load that may be divided equally on the load 

pivots or load cells of a section. [2.20]

(Added 2001)

section test. – A shift test in which the test load is applied over individual sections of the scale. This test is conducted 

to disclose the weighing performance of individual sections, since scale capacity test loads are not always available 

and loads weighed are not always distributed evenly over all main load supports. [2.20]

security means. – A method used to prevent access by other than qualified personnel, or to indicate that access has 

been made to certain parts of a scale that affect the performance of the device. [2.21]

security seal. – A uniquely identifiable physical seal, such as a lead-and-wire seal or other type of locking seal, a 

pressure-sensitive seal sufficiently permanent to reveal its removal, or similar apparatus attached to a weighing or 

measuring device for protection against or indication of access to adjustment. (Also see “approval seal.”) [1.10]

(Amended 1994)

selector-type. – A system of indication or recording in which the mechanism selects, by means of a ratchet-and-pawl 

combination or by other means, one or the other of any two successive values that can be indicated or recorded. [1.10]

semi-automatic zero-setting mechanism. – See “semi-automatic zero-setting mechanism” under “zero-setting 

mechanism.” [2.20]

sensitivity (of a nonautomatic-indicating scale). – The value of the test load on the load-receiving element of the 

scale that will produce a specified minimum change in the position of rest of the indicating element or elements of the 

scale. [2.20]
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sensitivity requirement (SR). – A performance requirement for a non automatic-indicating scale; specifically, the 

minimum change in the position of rest of the indicating element or elements of the scale in response to the increase 

or decrease, by a specified amount, of the test load on the load-receiving element of the scale. [2.20]

shift test. – A test intended to disclose the weighing performance of a scale under off-center loading. [2.20]

side. – That portion of a pump or dispenser which faces the consumer during the normal delivery of product. [3.30]

(Added 1987)

simulated-road test. – A distance test during which the taximeter or odometer may be actuated by some means other 

than road travel. The distance traveled is either measured by a properly calibrated roller device or computed from 

rolling circumference and wheel-turn data. [5.53, 5.54]

simulated test. – A test using artificial means of loading the scale to determine the performance of a belt-conveyor 

scale. [2.21]

single cell application load cell. – A load cell intended for use in a weighing system which incorporates one or more 

load cells. A single cell application load cell is designated with the letter “S” or the term “Single.” (Also see “multiple 

cell application load cell.”) [2.20]

(Added 1999)

single-tariff taximeter. – One that calculates fares at a single rate only. [5.54]

skirting. – Stationary side boards or sections of belt conveyor attached to the conveyor support frame or other 

stationary support to prevent the bulk material from falling off the side of the belt. [2.21]

slow-flow meter. – A retail device designed for the measurement, at very slow rates (less than 40 L (10 gal) per hour), 

of liquid fuels at individual domestic installations. [3.30]

small-delivery device. – Any device other than a large-delivery device. [3.34, 3.38]

span (structural). – The distance between adjoining sections of a scale. [2.20]

(Added 1988)

specification. – A requirement usually dealing with the design, construction, or marking of a weighing or measuring 

device. Specifications are directed primarily to the manufacturers of devices. [1.10]

static monorail weighing system. – A weighing system in which the load being applied is stationary during the 

weighing operation. [2.20]

(Added 1999)

strain-load test. – The test of a scale beginning with the scale under load and applying known test weights to 

determine accuracy over a portion of the weighing range. The scale errors for a strain-load test are the errors observed 

for the known test loads only. The tolerances to be applied are based on the known test load used for each error that 

is determined. [2.20, 2.22]

subordinate graduation. – Any graduation other than a main graduation. (Also see “graduation.”) [1.10]

subsequent distance or time intervals. – The intervals corresponding to money drops following the initial money 

drop. [5.54]

substitution test. – A scale testing process used to quantify the weight of material or objects for use as a known test load.

[2.20]

(Added 2003)
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substitution test load. – The sum of the combination of field standard test weights and any other applied load used 

in the conduct of a test using substitution test methods. [2.20]

(Added 2003)

surface gauge. – A combination of (1) a stationary indicator, and (2) a movable, graduated element designed to be 

brought into contact with the surface of the liquid from above. [4.42]

systematic (average) error ( X ) . – The mean value of the error (of indication) for a number of consecutive automatic 

weighings of a load, or loads, passed over the load-receiving element (e.g., weigh-table), shall be expressed 

mathematically as:

xx̅= ∑xx

nn

where: x = error of a load indication

n = the number of loads

[2.24]

T

tail pulley. – The pulley at the opposite end of the conveyor from the head pulley. [2.21]

take-up. – A device to provide sufficient tension in a conveyor belt so that the belt will be positively driven by the 

drive pulley. – A counter-weighted take-up consists of a pulley free to move in either the vertical or horizontal direction 

with dead weights applied to the pulley shaft to provide the tension required. [2.21]

tare mechanism. – A mechanism (including a tare bar) designed for determining or balancing out the weight of 

packaging material, containers, vehicles, or other materials that are not intended to be included in net weight 

determinations. [2.20]

tare-weighbeam elements. – The combination of a tare bar and its fractional bar, or a tare bar alone if no fractional 

bar is associated with it. [2.20]

taximeter. – A device that automatically calculates, at a predetermined rate or rates, and indicates the charge for hire 

of a vehicle. [5.54]

test chain. – A device used for simulated tests consisting of a series of rollers or wheels linked together in such a manner 

as to assure uniformity of weight and freedom of motion to reduce wear, with consequent loss of weight, to a minimum.

[2.21]

test liquid. – The liquid used during the test of a device. [3.30, 3.31, 3.34, 3.35, 3.36, 3.37, 3.38]

test object. – An object whose dimensions are verified by appropriate reference standards and intended to verify 

compliance of the device under test with certain metrological requirements. [5.58]

test puck. – A metal, plastic, or other suitable object that remains stable for the duration of the test, used as a test load to 

simulate a package. Pucks can be made in a variety of dimensions and have different weights to represent a wide range of 

package sizes. Metal versions may be covered with rubber cushions to eliminate the possibility of damage to weighing 

and handling equipment. The puck mass is adjusted to an accuracy specified in N.1.2. Accuracy of Test Pucks or

Packages. [2.24]

(Amended 2004)

test train. – A train consisting of or including reference weight cars and used to test coupled-in-motion railway track 

scales. The reference weight cars may be placed consecutively or distributed in different places within a train. [2.20]

(Added 1990) (Amended 1991)
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test weight car. – A railroad car designed to be a stable mass standard to test railway track scales. The test weight 

car may be one of the following types: a self-contained composite car, a self-propelled car, or a standard rail car.

[2.20]

(Added 1991)

testing. – An operation consisting of a series of volumetric determinations made to verify the accuracy of the volume 

chart that was developed by gauging. [4.42]

time recorder. – A clock-operated mechanism designed to record the time of day. Examples of time recorders are 

those used in parking garages to record the “in” and “out” time of day for parked vehicles. [5.55]

timing device. – A device used to measure the time during which a particular paid-for service is dispensed. Examples 

of timing devices are laundry driers, car-wash timers, parking meters, and parking-garage clocks and recorders. [5.55]

tolerance. – A value fixing the limit of allowable error or departure from true performance or value. (Also see “basic 

tolerances.”) [1.10]

training idlers. – Idlers of special design or mounting intended to shift the belt sideways on the conveyor to assure 

the belt is centered on the conveying idlers. [2.21]

transfer standard. – A measurement system designed for use in proving and testing cryogenic liquid-measuring 

devices. [3.38]

tripper. – A device for unloading a belt conveyor at a point between the loading point and the head pulley. [2.21]

U

uncoupled-in-motion railroad weighing system. – A device and related installation characteristics consisting of 

(1) the associated approach trackage, (2) the scale (i.e., the weighing element, the load-receiving element, and the 

indicating element with its software), and (3) the exit trackage, which permit the weighing of railroad cars uncoupled 

in motion. [2.20]

(Added 1993)

underregistration. – See “overregistration” and “underregistration.” [1.10]

unit price. – The price at which the product is being sold and expressed in whole units of measurement. [1.10, 2.20, 

3.30, 3.31, 3.32, 3.37, 3.39]

(Added 1992) (Amended 2019)

unit train. – A unit train is defined as a number of contiguous cars carrying a single commodity from one consignor 

to one consignee. The number of cars is determined by agreement among the consignor, consignee, and the operating 

railroad. [2.20]

unit weight. – One contained within the housing of an automatic-indicating scale and mechanically applied to and 

removed from the mechanism. The application of a unit weight will increase the range of automatic indication, 

normally in increments equal to the reading-face capacity. [2.20]

user requirement. – A requirement dealing with the selection, installation, use, or maintenance of a weighing or 

measuring device. User requirements are directed primarily to the users of devices. (Also see Introduction, 

Section D.) [1.10]

usual and customary. – Commonly or ordinarily found in practice or in the normal course of events and in 

accordance with established practices. [1.10]
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utility-type water meter. – A device used for the measurement of water, generally applicable to meters installed in 

residences or business establishments. excluding batching meters. [3.36]

(Added 2011)

V

value of minimum graduated interval. – (1) The value represented by the interval from the center of one graduation 

to the center of the succeeding graduation. (2) The increment between successive recorded values. (Also see 

“graduated interval.”) [1.10]

vapor equalization credit. – The quantity deducted from the metered quantity of liquid carbon dioxide when a vapor 

equalizing line is used to facilitate the transfer of liquid during a metered delivery. [3.38]

vapor equalization line. – A hose or pipe connected from the vapor space of the seller’s tank to the vapor space of 

the buyer’s tank that is used to equalize the pressure during a delivery. [3.38]

vehicle on-board weighing system. – A weighing system designed as an integral part of or attached to the frame, 

chassis, lifting mechanism, or bed of a vehicle, trailer, industrial truck, industrial tractor, or forklift truck. [2.20]

(Amended 1993)

vehicle scale. – A scale (including weigh-in-motion vehicle scales) adapted to weighing highway, farm, or other 

large industrial vehicles (except railroad freight cars), loaded or unloaded. [2.20]

(Amended 2021)

verification scale division, value of (e). – A value, expressed in units of weight (mass) and specified by the 

manufacturer of a device, by which the tolerance values and the accuracy class applicable to the device are determined. 

The verification scale division is applied to all scales, in particular to ungraduated devices since they have no 

graduations. The verification scale division (e) may be different from the displayed scale division (d) for certain other 

devices used for weight classifying or weighing in pre-determined amounts, and certain other Class I and II scales.

[2.20]

visible type. – A type of device in which the measurement takes place in a see-through glass measuring chamber.

[3.30]

vmin (minimum load cell verification interval). – The smallest load cell verification interval, expressed in units of 

mass* into which the load cell measuring range can be divided. [2.20, 2.24]

[*Nonretroactive as of January 1, 2001]

(Added 1996) (Amended 1999)

W

weighbeam. – An element comprising one or more bars, equipped with movable poises or means for applying 

counterpoise weights or both. [2.20]

weigh-belt system. – A type of belt-conveyor scale system designed by the manufacturer as a self-contained conveyor 

system and that is installed as a unit. A unit is comprised of integral components and, at minimum, includes a: 

conveyor belt; belt drive; conveyor frame; and weighing system. A weigh-belt system may operate at single or 

multiple flow rates and may use variable-speed belt drives. [2.21]

(Added 2015)

weighing element. – That portion of a scale that supports the load-receiving element and transmits to the indicating 

element a signal or force resulting from the load applied to the load-receiving element. [2.20, 2.21, 2.22]

(Added 1988)
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weigh-in-motion (WIM) vehicle scale. – A vehicle scale adapted to weighing vehicles as they travel across the scale 

without stopping. [2.20]

(Added 2021)

weigh-labeler. – An automatic weighing system that determines the weight of a package and prints a label or other 

document bearing a weight declaration for each discrete item (usually a label also includes unit and total price 

declarations). Weigh-labelers are sometimes used to weigh and label standard and random packages (also called 

“Prepackaging Scales”). [2.24]

(Amended 2004)

weigh module – The portion of a load-receiving element supported by two sections. The length of a module is the 

distance to which load can be applied. [2.20]

(Added 2013)

weighment. – A single complete weighing operation. [2.20, 2.21]

(Added 1986)

weight, unit. – See “unit weight.” [2.20]

weight classifier. – A digital scale that rounds weight values up to the next scale division. These scales usually have 

a verification scale division (e) that is smaller than the displayed scale division. [2.20]

(Added 1987)

weight ranges. – Electrical or electro-mechanical elements incorporated in an automatic indicating scale through the 

application of which the range of automatic indication of the scale is increased, normally in increments equal to the 

reading-face capacity. [2.20]

wet basis. – See “moisture content (wet basis).” [5.56(a), 5.56(b)]

wet hose. – A discharge hose intended to be full of product at all times. (Also see “wet-hose type.”) [3.30, 3.31, 3.38, 

3.39]

(Amended 2002 and 2019) 

wet-hose type. – A type of device designed to be operated with the discharge hose full of product at all times. (Also 

see “wet hose.”) [3.30, 3.32, 3.34, 3.37, 3.38, 3.39]

(Amended 2002 and 2019)

wheel-load weighers. – Compact, self-contained, portable weighing elements specially adapted to determining the 

wheel loads or axle loads of vehicles on highways for the enforcement of highway weight laws only. [2.20]

wholesale device. – Any device other than a retail device. (Also see “retail device.”) [3.30, 3.32]

wing pulley. – A pulley made of widely spaced metal bars in order to set up a vibration to shake loose material off 

the underside (return side) of the belt. [2.21]

Z

zero-load balance. – A correct weight indication or representation of zero when there is no load on the load-receiving 

element. (Also see “zero-load balance for an automatic-indicating scale,” “zero-load balance for a 

nonautomatic-indicating scale,” “zero-load balance for a recording scale.”) [2.20]

zero-load balance, automatic-indicating scale. – A condition in which the indicator is at rest at, or oscillates through 

approximately equal arcs on either side of, the zero graduation. [2.20]
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zero-load balance, nonautomatic-indicating scale. – A condition in which (a) the weighbeam is at rest at, or 

oscillates through approximately equal arcs above and below, the center of a trig loop; (b) the weighbeam or lever 

system is at rest at, or oscillates through approximately equal arcs above and below, a horizontal position or a position 

midway between limiting stops; or (c) the indicator of a balance indicator is at rest at, or oscillates through 

approximately equal arcs on either side of, the zero graduation. [2.20]

zero-load balance for a recording scale. – A condition in which the scale will record a representation of zero load.

[2.20]

zero-load reference (belt-conveyor scales). – A zero-load reference value represents no load on a moving conveyor 

belt. This value can be either; a number representing the electronic load cell output, a percentage of full scale capacity, 

or other reference value that accurately represents the no load condition of a moving conveyor belt. The no load 

reference value can only be updated after the completion of a zero load test.[2.21]

(Added 2002)

zero-setting mechanism. – Means provided to attain a zero balance indication with no load on the load-receiving 

element. The types of zero-setting mechanisms are: [2.20, 2.22, 2.24]

automatic zero-setting mechanism (AZSM). – Automatic means provided to set the zero-balance indication 

without the intervention of an operator. [2.22]

(Added 2010)

automatic zero-tracking (AZT) mechanism. – See “automatic zero-tracking (AZT) mechanism.” (NOTE: 

AZT maintains zero with specified limits. “Zero-setting sets/establishes zero with limits based on scale 

capacity.) [2.20, 2.22, 2.24]

initial zero-setting mechanism. – Automatic means provided to set the indication to zero at the time the 

instrument is switched on and before it is ready for use. [2.20]

(Added 1990)

manual zero-setting mechanism. – Nonautomatic means provided to attain a zero balance indication by the 

direct operation of a control. [2.20]

semiautomatic zero-setting mechanism. – Automatic means provided to attain a direct zero balance indication 

requiring a single initiation by an operator. [2.20]

(Amended 2010)

zero-setting mechanism (belt-conveyor scale). – A mechanism enabling zero totalization to be obtained over a whole 

number of belt revolutions. [2.21, 2.23]

(Added 2002)

zero-tracking mechanism. – See “automatic zero-tracking mechanism” under “zero-setting mechanism.” [2.20, 2.22, 

2.24]

zone of uncertainty. – The zone between adjacent increments on a digital device in which the value of either of the 

adjacent increments may be displayed. [2.20]
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