Scale Definitions Glossary

Scale Definitions Glossary

Readability, linearity, NTEP, divisions, uncertainty and other common industry terms can get confusing. There are a lot! But it doesn't have to be difficult. We've created a glossary of scale definitions and common terminology that are easy to understand. Use our glossary as a reference when you need information about specific terms. The glossary is in alphabetical order making it easy to find the definition you're looking for.

This is not an exhaustive list of scale definitions. Have a question or want something added? Let us know!

A

Accuracy

How well a scale can display the weight of a sample relative to the true weight of the sample. This is closely related to the combination of the display resolution and consistency of the performance of the scale.

Accumulation

A common weighing mode to determine a total "accumulated" weight of multiple samples. After one sample is weighed, the result is stored in memory. The next sample is weighed and can be added to the weight of the first sample to give you the total accumulative weight.

Adjustment

Common term used for any mechanical or software changes made to a weighing scale usually during calibration.

Ambient Conditions

Related to temperature, humidity and air pressure. Standard environmental conditions at room temperature, which is typically accepted as 70° Fahrenheit.

Analytical Balance

Analytical balances are typically found in laboratories. They are a class of balance capable of displaying results into the sub milligram range.

Animal Weighing

Weighing mode for weighing animals. Also referred to as dynamic weighing. Animal weighing takes into consideration movements or shifting of the load commonly associated with an animal moving on the weighing platform during measuring.

APW

Stands for Average Piece Weight. Commonly associated with parts counting applications. APW is the determined average weight of an individual piece based on the total weight of a sample divided by the number of pieces weighed.

Approvals

National standards, regulations or certifications that weighing equipment is in compliance with.

ASTM

ASTM International is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services. Learn more about ASTM

Automatic Door

Automatic doors are typically motorized draft shield doors on analytical and precision balances. Automatic doors prevent the operator from having to make direct contact with the draft shield doors during operation.

B

Backlight

Most commonly used with LCD displays. A backlight is a light that illuminates the LCD display to make it easier to read.

Balance

Commonly used interchangeably with scale. Weighing scale or weighing balance. However, many people associate balances with laboratory weighing instruments such as analytical, semi micro, and microbalances.

Base

The platform of a bench scale or weighing scale where samples are weighed. Also commonly referred to as the weighing base or platform. This includes the loadcell or loadcells, frame that holds the loadcells, and the weighing platter or pan.

Baud Rate

Baud rate is the rate at which information is transferred in a communication channel. In the serial port context, "9600 baud" means that the serial port is configured to transfer 9600 bits per second.

Below Balance Weighing

Also known as under hook weighing. Below balance weighing uses an integrated hook in a scale or balance to hang samples from. This is most commonly used with density determination kits.

Bench Scale

Bench scales are usually compact scales that are used on a bench, or table top, as the name would imply. Often times, bench scales are also referred to as platform scales because it is common for the weighing base to be separate from the indicator. However, single unit compact scales are often referred to as bench scales as well because of their use on a work surface.

Bind

A bind is something that physically inhibits the scale to operate properly.  Usually it is something that physically touches the weighing mechanism.  A common example is when a floor scale is pushed up against a wall.  If the scale base is touching the wall it won't be able to move up and down freely.

Breeze Break

Also referred to as a draft shield. A breeze break blocks drafts from the weighing chamber which could affect weighing results in three-place gram balances or sub-milligram balances. Even a slight draft from someone passing by can cause the display to fluctuate.

C

Calibration

The action of verifying and adjusting an instrument using test standards of a known documented weight. Calibrating a scale against test standards ensures that the scale is performing as it should and is accurate to the manufacturers stated specifications.

Calibration Report

A document that provides as found and as left data pertaining to the accuracy of a weighing scale or balance. Also known as a calibration certificate, a calibration report is typically completed by a certified scale technician, registered scale service agency or ISO accredited lab.

Capacity

Maximum weight a scale can handle without taking into consideration overload protection if applicable.

Checkweigher

A checkweigher is a scaled used to verify a selected weight within programmed limits. An operator sets a pre-determined weight and once the desired weight is reached, the checkweighing scale will provide an audible or visible indication to the operator. Checkweighers are commonly used in filling applications where an operator fills and weighs a product to ensure consistent weight.

Checkweighing

Checkweighing is the process of verifying the weight of a product based on pre-determined values. Commonly used for filling applications. See "checkweigher" above for more specific applications.

Class

Scales are classified based on the number of scale divisions and the value of the scale division (d or e). Classes are a way of designating intended use for the scale.

Communication

Refers to the capability of a scale or balance to connect to and communicate with peripheral devices such as computers, printers, barcode scanners and other devices. Also referred to as the interface, or communication interface.

Counting Scale

A scale used for counting parts and pieces. Weight is determined for a sample and saved in the scale. The scale can then calculate how many parts there are on the pan based on the APW and total weight.

Crane Scale

Also known as a hanging scale, a crane scale is an overhead weighing scale commonly used in heavy-capacity industrial lifting applications. Often times, crane scales are used in warehouses and production facilities to move heavy objects from one area to another. The crane scale can measure the weight of a load which can be used for quality or logistics purposes.

D

Density Determination

Density determination is a method of finding the density of a solid or liquid using a scale or analytical balance. Density determination is often performed using under-hook weighing and a specialized kit. These kits are available as an accessory for any scale model that offers density determination as a weighing application.

Digital Scale

A scale that is electronic, not mechanical. Digital scales are the most common weighing scales on the market today. People buy digital scales for a large variety of weighing applications from analytical to heavy capacity. Digital scales are found almost everywhere. People use digital scales at home to weigh themselves for health purposes, delis use them to weigh foods, manufacturers to weigh shipments and the list goes on.

Display

A display is where the measurement results are shown. This can be a digital readout like with a LCD display or a beam display on a mechanical scale.

Division

A scale division is commonly interchanged with readability and resolution. A division is the smallest increment of weight that the digital display will show. A division can be determined by taking the scale's capacity divided by the scales readability.

Discrimination

Discrimination refers to how well a digital scale can display the weight of a very small sample or when a sample changes by a very small amount.  A test load or change in test load equal to 1.4 divisions is normally used when performing a discrimination test on a digital scale.

Draft Shield

Also known as a breeze break. A draft shield is typically associated with analytical balances that have a readability of 0.001 grams or better. The draft shield protects the weighing pan from air movement commonly associated with ventilation systems and persons walking by the balance.

Drift

Drift is a term used to describe when a a digital scale display does not remain steady. The reading on the display will fluctuate up or down. Drift is usually caused by environmental influences such as drafts. Drift can also be caused by defects in the scale.

Dynamic Weighing

Dynamic weighing, also often times referred to as animal weighing, is an application that determines weight even when conditions aren't ideal. For example, while weighing an animal, it is likely that the animal will move during the process which can throw off the results. Dynamic weighing application takes this into consideration and is able to determine a weight even in unsatisfactory conditions.

E

Eccentric Loading

Eccentric loading is when a weight is not placed on the center of the weighing platform.  The ability of a scale to display the same value when a weight is placed anywhere on the weighing platform is checked by performing a shift test.  

Electro-mechanical Scale

A scale that is partly digital and partly mechanical. Usually these are scale systems where the scale base is mechanical and instead of a mechanical beam display a loadcell is integrated along with a digital weight indicator.

Ethernet

Ethernet is a system for connecting a number of computer systems or devices to a local network. An Ethernet cable is used to form the connection. Some scales offer Ethernet communication ports as a method of connection to software and local networks.

External Calibration

A scale with external calibration does not offer an automatic, or internal, calibration feature. The scale must be calibrated using test standards and must be performed by an operator.

F

FM Approved

Factory Mutual, or FM approved, scales and scale components are approved to operate in hazardous and combustible environments. Corresponds with intrinsically safe equipment.

Filling

Filling is a common application that uses weighing scales to fill a container or packaging to a determined capacity based on weight. Filling scales typically offer a feature that uses a relay switch to shut off an filling apparatus when the target weight is reached. This is especially useful in manufacturing and packaging processes.

Floor Scale

Also known as a platform scale. A floor scale is a large weighing base for higher capacity weighing such as what is typically required in shipping and receiving departments. Floor scales are commonly used to weigh shipping pallets full of material. 

Food Scale

Scale used for weighing foods. Also known as ingredient scales, portioning scales and restaurant scales. Food scales are commonly stainless steel and feature higher washdown ratings for easier cleaning.

Formulation

Formulation is a weighing application that uses pre-determined weights for individual ingredients to accurately produce a final product. Many scale manufacturers offer scale hardware and software to accommodate formulation weighing.

G

GLP

GLP stands for Good Laboratory Practices. As it relates to scales, GLP typically refers to data management and export such as with printing weighing results and assigning unique IDs.

H

Handbook 44

Handbook 44 is a NIST (National Institute of Standards and Technology) publication that provides "specifications, tolerances, and other technical requirements for weighing and measuring devices." Learn more about NIST Handbook 44.

Hopper Scale

Hopper scales are containers with loadcells integrated into them for weighing dry bulk materials.  Usually dry bulk material is fed into the hopper, weighed, and then emptied into a mixer or package. Hopper scales are commonly used in industrial and agricultural applications where bulk materials are mixed, packaged and sold.

Housing

A housing refers to the cover, or enclosure, that houses a scale or indicator's internal and electronic components.

Hysterisis

Hysterisis is when the displayed value of a known weight is different depending on the direction of loading. An example of this would be if a 5 lb weight is placed on a scale and the scale displays 5.00 lbs but when the weight is removed from the scale it displays 0.01 lbs instead of returning all the way to 0.00 lbs.

I

Indicator

Also known as a weight display or controller. An indicator is a device that typically controls a weighing scale or balance and also displays the menu and weighing results. Indicators are commonly used in industrial applications where a scale base doesn't have the weight display integrated into the same housing.

Industrial Scale

A very broad term for scales that are typically used in industrial and/or manufacturing applications.

In-use Cover

Usually a molded plastic cover that sets over top of a scale or balance display and keypad to protect it from debris, spills and splashes. An in-use cover helps to prolong the life of a scale or balance.

Interface

Also known as communication interface. An interface is one or a group of input or output ports that allow a scale or balance to connect to an external device through the use of RS-232, USB, Ethernet or other connection methods.

Intrinsically Safe

Intrinsically safe equipment is defined as "equipment and wiring which is incapable of releasing sufficient electrical or thermal energy under normal or abnormal conditions to cause ignition of a specific hazardous atmospheric mixture in its most easily ignited concentration." Intrinsically safe scales, balances and indicators are typically used in environments where there are combustible fumes or materials. An example of this could be paint and chemical manufacturers.

Internal Calibration

Internal calibration is a feature some scales have that allows calibration of the scale using a built-in mass standard. A physical weight and motorized mechanism built into the scale allows the user to calibrate the scale through menu prompts. Some brands and models also offer automatic internal calibration in which the scale performs its own calibrations based on preset parameters including time, temperature and environmental changes.

IP Rating

IP, or Ingress Protection, ratings are defined in international standard EN 60529. They are used to define levels of sealing effectiveness of electrical enclosures against intrusion from foreign bodies (tools, dirt etc) and moisture. The Enclosure Company provides a great resource explaining IP Ratings.

IR Sensor

IR stands for infrared. An infrared sensor is typically found on analytical balances and can detect hand movements. Tasks such as tare, zero and print can be performed hands-free with a simple wave of a hand.

ISO

ISO is an acronym for the International Organization for Standardization. ISO is an international standard-setting body composed of representatives from various national standards organizations including standards for weighing metrology such as calibration methods, practices and procedures. Learn more about ISO.

J

Jewelry Scale

A scale commonly used in jewelry establishments that can weigh in carats and other measurement units commonly associated with the jewelry industry.

L

Laboratory Balance

A very broad term for balances that are used in laboratories or research applications.

Legal-for-Trade

In general, any person or business that buys, sells, or charges based upon weight within the United States must use a Legal-for-Trade scale. NTEP approved scales are certified for use in legal-for-trade applications. NTEP stands for National Type Evaluation Program and is a non-profit organization that certifies legal-for-trade scales.

Level Indicator

Commonly a mechanical level bubble or an electronic display on a scale or balance that visually verifies to the operator that the scale or balance is level. It is important that a scale is level to ensure accurate weighing results.

Linearity

Linearity is the ability of a scale or balance to display the correct value throughout the full capacity range of the scale. Linearity is tested by placing known weights on the scale from near zero, mid capacity and full capacity.

Load Cell

A load cell is a type of transducer which turns force into a measurable electrical output. Although there are many varieties of load cells, strain gauge load cells are the most common. Load cells are used in weighing scales and balances to determine weight based on the force exerted by the sample placed on the pan.

M

Mass

Mass is a physical property of a material. The mass gives a material weight when gravity pulls the material toward earth. The units of mass are gram and kilogram. The terms mass and weight are often used interchangeably.

Mechanical Scale

A scale that is not digital. A mechanical scale does not use any electronics and relies on physical components to produce weight results. Mechanical beam scales are a good example. Measurements are taken using a combination of counterweights, rods, levers and springs.

Menu

For digital scales and balances, the menu is where an operator makes selections and operates the instrument. An operator can navigate through a menu using keys and prompts to perform specific tasks.

Microbalance

A microbalance is an analytical balance that has a readability of 0.001 mg or better. These are used for extremely precise weighing applications, typically research, and for samples that are typically no heavier than 25 grams.

Minimum Weight

Minimum weight is a manufacturer's suggested specification for the minimum weight a sample must be for the scale to measure accurately. If the sample is below the manufacturer's recommendation, the results could be inaccurate. In some instances, the sample will not produce a result on the display at all.

Moisture Balance

Also known as a moisture analyzer, a moisture balance is used to determine the moisture content of sample at set temperatures. The moisture balance uses a combination of weighing and heating methods to determine moisture content.

Mole Weighing

No, we're not talking about weighing those weird looking mammals that burrow under the ground. We're talking about molar mass, which is defined as the mass of 6.02 x 1023 atoms of a given element or compound. Mole weighing allows scientists to determine how many moles are in a given sample based on the sample's molar mass which is entered into the scale.

Multiple Weighing Units

This is a term used to describe which units a weighing instrument is capable of displaying. For instance, some scales may only accommodate pounds and kilograms, while others can support grams, ounces, pounds, kilograms, pound-ounces and more.

N

NTEP

NTEP (National Type Evaluation Program) Committee is responsible for the oversight of NTEP. NTEP evaluates and approves weighing instruments used in legal-for-trade applications. Learn about NTEP.

Net Weight

Net weight is the weight of a product or sample less the container or vessel it is being weighed in. Net weight can also be the "total weight" of a collection of sample weights collected over a duration of time.

O

Operating Temperature

The ideal temperature for an instrument to operate in. As is true with most electronics, if the environment is too cold or too hot, failure can occur or accuracy can decline. A weighing scale, especially digital scales, should be operated within the defined operating temperature range to ensure accuracy.

Overload Rating

Overload rating is the manufacturer's specification for the most weight an instrument can handle before the possibility of internal damage occurs. Exceeding the overload rating can damage the scale and may also have dangerous safety concerns for equipment such as crane scales, truck scales and other potentially dangerous heavy-capacity instruments. It is highly recommended to understand the maximum overload rating of your scale before you use it. Refer to the manufacturer's user manual or data sheet.

P

Pan

Also known as a platform or platter. A pan is the area of a scale that a sample is placed on to take the measurement.

Parts Counting

The action of counting parts using a weighing scale. Refer also to counting scale.

Percent Weighing

Percent weighing is the process of using a scale or balance to determine the weight of an item as a percentage of a reference weight. This application is commonly used in commercial baking where ingredients are weighed based on a percentage of the flour weight; also known as Baker's Percentage.

Pipette Adjustment

Pipette adjustment is a weighing application used to verify and calibrate pipettes. This is usually performed at a high degree of precision using an analytical balance, typically a semi-micro or above. Some manufacturers provide a kit for pipette adjustment which includes the balance, software and consumables.

Platform Scale

Can also be referred to as a floor scale or bench scale. The term platform scale is commonly interchangeable with either of the two aforementioned scale types. "Platform" typically refers to a scale that has a weighing base, or pan, separate from a display, or indicator.

Portable Balance

A weighing balance that is easy to transport or that can be used in the field.

Portioning Scale

Also referred to as an ingredient scale or food scale. A portioning scale is used for measuring the weight of food to get the desired size, or portion. They are commonly used for specific health diets and food processing.

Price Computing Scale

Price computing scales are also referred to as retail scales. Price computing scales often times feature a PLU (price lookup) memory to quickly recall the price per unit of a particular commodity. A good example of an application where a price computing scale would be used is a farmers market. Produce or vegetables sold by weight are measured on the scale and a price is calculated based on the weight. The consumer pays the displayed total on the scale.

Power

The electrical power supplied to an instrument. Manufacturers will list power data in their specifications which may include amps, wattage and voltage. There are also different types of power supplies including AC adapters, disposable batteries and/or rechargeable batteries.

Precision Balance

A precision balance is a laboratory balance that has a readability of 0.001 gram or less. Often times, precision balances are referred to as top-loading balances because they do not require a draft shield. Some precision balances, however, do include a draft shield. 

R

Readability

Commonly referred to as division size or resolution. 

Repeatability

Repeatability is the capability of a scale to display the same value when a weight is placed on the pan more than once. Repeatability is often expressed as a standard deviation of multiple tests using the same amount of test weight. 

Reproducibility

Reproducibility is the capability of a scale to perform consistently even when conditions change.  An example of this would be that a scale in an outdoor environment displays the same weight value when a known weight is placed on it at 40 degrees F and at 75 degrees F.

Resolution

Resolution is also commonly referred to as readability or division size. The terms are often times interchanged. As it pertains to digital scales, resolution is the smallest change in mass that corresponds to a change in displayed results. Simply put, resolution is the amount the scale will increment by as weight is added or removed.

Retail Scale

A broad term used to define a group of scales used in retail applications. These could include price computing scales, shipping scales and food scales.

RS-232

RS-232 is a type of serial communication used to transmit data between devices such as computers and printers. RS-232 is also commonly used in a wide variety of weighing equipment. Scales that offer a RS-232 interface can be connected to computers and peripheral devices using a RS-232 cable.

S

Scales Outlet

Scales Outlet is a trusted source for purchasing weighing equipment including digital scales, analytical balances, heavy-capacity scales, scale accessories and more. Scales Outlet is often referred to as a leading online scale dealer and a reliable resource for everything weighing. This is just what we've heard. It is not yet included in the dictionary.

Security Bracket

An integrated bracket, typically built into the base or housing, that can be used to secure a scale or balance. This helps to prevent unwarranted relocation or theft of the device.

Semi-Micro Balance

A semi micro balance is a laboratory balance that has a readability of 0.01 mg. Some dual-range analytical balances are also referred to as a semi-micro balances when one range of the capacity has a readability of 0.01 mg. 

Sensitivity

Sensitivity refers to how well a mechanical scale reacts to a very small sample or when a sample changes by a very small amount.  A test load or change in test load equal to 1 divisions or 2 divisions is normally used when performing a sensitivity test on a mechanical scale.

Sensitivity Drift

Sensitivity drift is the effect temperature change has on the performance of a scale. Sensitivity drift specifications are usually provided for instruments with higher readability, such as semi-micro and micro balances.

Shift Test 

A shift test verifies the ability of a scale to display the same result no matter where the sample is placed on the weighing pan. This is also known as a corner-load test. Scale technicians will perform a shift test to verify that a scale is consistent at all four corners and center of the platform.  In a shift test a known weight is weighed in the center of the platform and at the center of each quadrant of the pan or at each corner. Usually the known weight is equal to 1/4 or 1/3 of the scale capacity.

Shipping Scale

Any scale that is used for shipping, warehousing and logistics purposes. Some shipping scales have special programming for communicating with freight carrier companies such as UPS®, FedEx® and USPS® to calculate shipping rates based on weight provided from the scale. This is typically accomplished through connection to a PC and shipping software.

Stabilization Time

The amount of time it takes for a scale or balance to stabilize after a sample is placed on a weighing pan. Stabilizing time is determined from the time the sample is placed on the pan to the time the display shows the final result.

Stable Indicator

Some digital scales incorporate a stable indicator into the display to show the operator visually when a weighing result is final. The scale will show "stable" when the sample weight has been determined.

Stabilization Time

The amount of time it takes for a scale to produce a final weighing result on the display. The time elapsed from the moment a sample is placed on the platform to the moment the weighing result is stable is considered the stabilization time.

Storage Conditions

Suggested conditions for storage of scales. Manufacturers typically provide ideal storage conditions for instruments that are not in use. This information is usually found in the user manual and should be followed to help facilitate longer life and sustained accuracy.

T

Tank Scale

Similar to hopper scales except tank scales are used for weighing bulk liquid materials. See definition for hopper scale above.

Tare

Tare is the subtraction of the weight of a container from the overall measurement of the container and sample being weighed. For example, if you place a box of bolts on a scale and you want the weight of just the bolts, you'll need to remove the weight of the box itself from the result. To do so, you'd "tare" the scale removing just the weight of the boxes' known value, or through a keypad function taring the scale with just the box on it.

Temperature Range

Temperature range has various meanings depending on the application. For a moisture balance, the temperature range would be the heating range the moisture balance can facilitate. As it pertains to most other scales, the temperature range might also be referred to as the operating temperature range, which is the ideal temperature the scale or balance should be used in.

Truck Scale

A truck scale is a heavy-capacity scale used to weigh large trucks such as semis, dump trucks and other heavy load vehicles. Truck scales are available in a variety of sizes, styles and capacities. They are also sometimes referred to as heavy capacity vehicle scales.

U

Underload

Opposite of overload. Underload is used to describe a situation where a sample does not weigh enough for a particular scale's minimum weight recommendation. An underload is outside the minimum range of the scale which can result in inaccurate results or no results at all.

USP Minimum Weight

In the pharmaceutical industry, the United States Pharmacopoeia’s (USP) set of standards for managing balances is widely recognized around the world. Minimum weight is the minimum sample quantity required to perform an accurate quantitative analysis were the measurement error of the balance used is taken into account.

V

Verification

Verification is a term used to describe the process of verifying a scale is working properly. This usually goes hand-in-hand with calibrating a scale or inspecting a scale for accuracy. Verification involves using certified test weights to check the accuracy of a scale or balance. Also known as a verification process.

W

Washdown Scale

A washdown scale features a high IP rating that protects the scale from dust, dirt and water. Washdown scales are ideal for use in harsh environments that are wet, dirty and generally considered a bad environment for digital scales. Washdown rated scales are designed specifically for these types of environments.

Weighbridge

Another term for truck scale or heavy capacity vehicle scale. A weighbridge is technically defined as any large capacity weighing scale that is anchored to a concrete platform or foundation.

Weighing

By definition, weighing is the process of determining how heavy and object is. This is the primary function of weighing scales and balances. They are designed to determine how heavy objects are, some of which are capable of doing so to an extremely high degree of accuracy.

Weighing Applications

A weighing application is a designated use for a weighing scale. Scale manufacturers will list the weighing applications their hardware and software is capable of performing. Examples of weighing applications are dynamic weighing, percent weighing, filling, parts counting and of course, basic weighing.

Weighing Unit

Also referred to as a measurement unit or unit of measure. Examples of weighing units are pounds (lbs), grams (g), ounces (oz), kilograms (kg) and pound ounces (lb:oz).

Weight

The actual definition of weight is "a body's relative mass or the quantity of matter contained by it, giving rise to a downward force; the heaviness of a person or thing." Simply put, weight is how much something weighs by a given unit of measure. A weight can also be a physical object, such as a test weight or mass standard. For example, a 100 gram weight used to calibrate an analytical balance.

Weigh-below Hook

A built-in hook on the underside of a scale or balance used to hang samples to determine a weight. Typically associated with analytical balances and research weighing applications, such as density determination.

Z

Zero

Also commonly referred to when taring a scale, however, they aren't exactly the same. You can "zero" a scale using the tare function when negating a container weight, however, zeroing a scale is just setting the display to show zero regardless of what is or isn't on the platform. Zeroing a scale can be thought of as "resetting" the display to zero. Some scales and balances have a built-in feature that ensures the display always returns to zero when the pan is emptied.