A reference guide to the most important terms, acronyms, and concepts in industrial and commercial weighing. Each definition links to the full article where the concept is covered in depth.
A
Average Piece Weight (APW): The weight of a single unit within a batch of identical parts, calculated by a counting scale by dividing the total sample weight by the number of sample pieces. The APW is the foundation of all weight-based counting and is stored in the scale’s memory for recall on future counting cycles. → What Is a Counting Scale?
Analytical Balance: A high-precision laboratory weighing instrument capable of measuring to 0.0001 g (0.1 mg) or finer. Used in pharmaceutical, chemical, and research applications where the highest level of accuracy is required. Distinct from a precision balance, which typically resolves to 0.01 g. → Analytical Balance vs Precision Balance
B
Bench Scale: A compact weighing instrument designed to sit on a workbench or countertop. Typically used for loads that can be hand-placed — components, packages, ingredients, and small assemblies — with capacities from 5 lb to approximately 600 lb and readability finer than most floor scales. → Bench Scale vs Floor Scale
C
Calibration: The process of comparing a scale’s readings against a known reference standard (certified test weights traceable to NIST) and adjusting the scale so that its readings fall within the required tolerance. Distinct from verification, which checks accuracy without necessarily adjusting it. → How Often Should Industrial Scales Be Calibrated?
Certificate of Conformance (CC Number): The unique number issued by NTEP to a scale model that has passed the type evaluation testing required by NIST Handbook 44. Every NTEP-certified scale carries a CC number on its data plate. CC numbers are publicly searchable in the NCWM database at ncwm.com/ntep.
Checkweigher: A weighing system that automatically verifies the weight of every product or package passing through a production line, comparing each item against pre-set upper and lower limits and rejecting items outside the acceptable range. Used in food processing, pharmaceutical manufacturing, and packaging operations. → What Is a Checkweigher?
Counting Scale: A digital weighing instrument that determines the number of identical parts in a batch by measuring their combined weight and dividing by the average piece weight. Used in manufacturing, warehousing, and distribution for parts counting and inventory management. → What Is a Counting Scale?
Crane Scale: A heavy-duty electronic weighing instrument that suspends between a crane hook and the load to measure weight during lifting operations. Uses internal load cells to convert the tension force of the suspended load into a digital weight reading. → How to Choose a Crane Scale
D
Dead Weight: The weight of the empty container, pallet, or packaging material placed on a scale before the product is loaded. Zeroed out using the tare function so that only the net product weight is displayed.
Division (Scale Division): The smallest increment a scale can display. Also called readability or graduation. A scale with 0.1 lb divisions displays weight in increments of 0.1 lb. Higher-capacity scales typically have coarser divisions; higher-precision scales have finer divisions.
E
Explosion-Proof Scale: A weighing instrument certified for use in environments where flammable gases, vapors, or dusts may be present in the atmosphere. Designed and tested to prevent any internal electrical arc or heat from igniting the surrounding hazardous atmosphere. Carries NEC class and division certifications in the US. → What Is an Explosion-Proof Scale?
F
Floor Scale: A heavy-duty weighing platform placed directly on the floor, designed to accommodate loads that are too large or heavy to be lifted onto an elevated surface — typically 1,000–20,000 lb capacity. Loaded using forklifts, pallet jacks, or hand trucks. → How to Choose a Floor Scale
G
GMA Pallet: A standard North American pallet measuring 48″ × 40″ (the Grocery Manufacturers Association standard). The most common pallet dimension in US warehouse and distribution operations. A 4 ft × 4 ft floor scale platform accommodates a GMA pallet with margin on all sides.
Gross Weight: The total weight of a load, including its packaging, pallet, or container. Contrast with net weight, which is the weight of the product only after the tare weight has been subtracted.
I
Ingress Protection (IP) Rating: A standardized rating system defined by IEC 60529 that classifies how well an electrical enclosure resists the intrusion of solid particles (first digit) and liquids (second digit). Common ratings for industrial scales include IP65, IP67, and IP69K. → IP Ratings for Industrial Scales Explained
Internal Resolution: The number of divisions the scale uses internally to calculate weight — distinct from the displayed readability. Higher internal resolution produces more accurate average piece weight calculations in counting scales, enabling accurate counting of lighter parts. → What Is a Counting Scale?
ISO/IEC 17025: The international accreditation standard for testing and calibration laboratories. A calibration provider accredited to ISO/IEC 17025 can demonstrate that its reference standards are NIST-traceable and that its procedures meet international quality requirements — the standard required for ISO 9001, GMP, and legal-for-trade calibration compliance.
L
Legal-for-Trade: A designation for a scale that meets the requirements of NIST Handbook 44 and has been verified by a state Weights and Measures inspector for use in commercial transactions where weight determines price. Requires NTEP certification from the manufacturer as a prerequisite.
Load Cell: The primary sensing element inside a digital scale. A load cell is a force transducer that converts the mechanical force of a weight into an electrical signal proportional to that force. Most industrial scales use strain gauge load cells; high-precision scales may use electromagnetic force restoration (EMFR) load cells.
M
Maximum Allowable Variation (MAV): The maximum permissible under-fill of an individual package below the declared net weight, as defined in NIST Handbook 133. An individual package with a minus error exceeding the MAV fails net content compliance regardless of the batch average. → What Is a Checkweigher?
Mild Steel: A low-carbon steel alloy (approximately 0.05–0.25% carbon) used as a platform material for industrial scales in dry indoor environments. Requires a powder coat or paint coating for corrosion resistance. Not suitable for food processing, washdown, or outdoor environments without additional protection. → Stainless Steel vs Mild Steel Industrial Scales
N
NCWM: National Conference on Weights and Measures. The non-profit organization that administers NTEP testing, adopts amendments to NIST Handbook 44, and coordinates weights and measures policy across US states and territories.
Net Weight: The weight of a product only, excluding the weight of its packaging, container, or pallet. Determined by subtracting the tare weight from the gross weight.
NIST: National Institute of Standards and Technology. The US federal agency responsible for publishing NIST Handbook 44 and NIST Handbook 133, maintaining primary measurement standards, and providing technical guidance to the National Conference on Weights and Measures.
NIST-Traceable: A measurement result or calibration certificate is NIST-traceable when the reference standards used can be linked to the primary measurement standards maintained by NIST through an unbroken chain of documented calibrations.
NTEP: National Type Evaluation Program. The program administered by NCWM through which scale models are tested against NIST Handbook 44 requirements and issued a Certificate of Conformance (CC number). NTEP certification is the first step toward legal-for-trade approval in the United States.
P
Pallet Jack Scale: A hybrid device combining a standard hydraulic pallet jack with an integrated digital weighing system. Allows the operator to lift, weigh, and move a pallet in a single operation without transferring the load to a stationary floor scale. → What Is a Pallet Jack Scale?
Pit Frame: A steel frame installed in a recessed concrete pit that allows a floor scale to sit flush with the surrounding floor level. Eliminates the need for approach ramps and allows forklifts and pallet jacks to drive directly onto the scale platform.
R
Readability: The smallest weight increment displayed by a scale indicator. Also called display resolution or graduation. Distinct from accuracy — a scale may display to 0.1 lb but have an accuracy of ±0.5 lb. Also distinct from internal resolution, which is the finer internal calculation used by counting scales.
S
Stainless Steel: An iron-based alloy containing a minimum of 10.5% chromium that forms a self-repairing passive oxide layer, providing inherent corrosion resistance without requiring a surface coating. The standard material for food processing, pharmaceutical, washdown, and outdoor industrial scale platforms. → Stainless Steel vs Mild Steel Industrial Scales
T
Tare: The function that subtracts the known weight of an empty container, pallet, or packaging from the gross weight reading, leaving only the net product weight displayed. The tare function is standard on all digital industrial scales.
Tare Weight: The weight of the empty container, pallet, or packaging that is subtracted from the gross weight to determine the net product weight.
W
Weights and Measures Inspector: A state or local official authorized to inspect, verify, and seal commercial weighing equipment in accordance with NIST Handbook 44. A scale must be verified and sealed by a Weights and Measures inspector before it can be legally used for commercial transactions, regardless of its NTEP certification status.
This glossary is updated as new articles are published on Scale Blog. Last updated: April 2026. Have a term you would like defined? Contact us.