Glossary of Weighing Terminology

We’ve compiled a handy list of weighing terminology used throughout our website and within different industries that we supply and support with our weighbridges and other industrial weighing scales.

Accuracy

in weighing systems refers to how close the measured weight of a load is to its true or actual weight. It is an important performance characteristic of weighing systems, as it impacts the reliability and consistency of the measurements. Accuracy is influenced by a variety of factors such as the quality of the load cells, the stability of the weighing platform, the calibration of the system, and the environment in which it operates. High accuracy is critical in many industries, such as pharmaceuticals, food and beverage, and chemical processing, where precise and consistent measurements are required to ensure product quality, safety, and regulatory compliance. In contrast, lower accuracy requirements may be acceptable in applications where precision is less critical, such as in bulk material handling or mining operations.

Adjustment

The process of modifying a weighing instrument’s parameters to ensure it provides readings within specified tolerances. Adjustment often follows calibration if the instrument is found to be outside acceptable limits.

Analogue Load Cell

A load cell that outputs a continuous electrical signal (typically voltage or current) that is proportional to the applied force. This signal usually requires processing by an external indicator or transmitter to be displayed or used.

ANPR

ANPR stands for Automatic Number Plate Recognition. It is a technology that uses optical character recognition (OCR) to automatically read and capture the license plate numbers of vehicles. ANPR systems use cameras to capture images of passing vehicles and then analyze the images to extract the characters on the license plate. The captured information can then be used for various purposes, such as tracking vehicle movements, identifying stolen vehicles, or enforcing parking regulations. ANPR technology is used in a variety of applications, including law enforcement, toll collection, and parking management.

Axle weight

the weight of the vehicle supported by each individual axle.

Axle weigher

An axle weigher, also known as an axle scale, is a type of weighing system used to determine the weight of individual axles or groups of axles on vehicles. It consists of a platform or plates placed on the ground, the load cells measure the weight of the vehicle as it drives over the platform. Axle weighers can be portable or permanent installations, and may be used for various applications such as weighing trucks at weigh stations, monitoring load distribution, and checking compliance with weight limits on roads and bridges. Though software, single axle weighers can be used to determine the weight of the whole vehicle as each axle passes over the scale.

Batch weighing

A process that involves weighing a predetermined amount of material for a specific purpose, such as recipe formulation or inventory control.

Belt scale

A Belt scale or Belt weigher is weighing system that measures the weight of material moving on a conveyor belt. Usually sections of the conveyor belt frame is fitted with a load cell system. Belt weighers are common in mining operations as well agriculture, food processing, waste management and construction.

Bending Beam Load Cells

Bending beam load cells are used in applications where high accuracy and low capacity is required. They are commonly used in laboratory balances, medical devices, and low-capacity industrial scales.

Bogie weigher

A train weighing system used to measure the weight of each bogie (a frame carrying a pair of axles) of a train separately.

Calibration

the process of comparing the readings of a weighing instrument against known standard weights to determine its accuracy and ensure precise measurements. Calibration verifies if the instrument is performing within acceptable tolerances.

Canister Load Cells

Canister load cells are heavy-duty load cells that are designed for use in harsh environments such as construction sites, mines, and offshore platforms. They are typically used in high-capacity applications such as weighbridges, silos, and tanks.

CE Marking

A certification mark indicating conformity with health, safety, and environmental protection standards for products sold within the European Economic Area (EEA). Weighing equipment sold or used in the EEA often requires CE marking.

Checkweigher

A system that checks the weight of a product against a pre-set target weight and rejects products that fall outside of the acceptable weight range.

Compression Load Cells

Compression load cells are designed to measure compressive forces and are commonly used in industries such as automotive, aerospace, and construction. They are often used in testing and monitoring applications, such as measuring the force required to compress a spring or the pressure inside a container.

Digital Load Cell

A load cell featuring integrated electronics that convert the analogue force measurement into a digital signal within the load cell itself. This can offer advantages like improved signal integrity, easier calibration, and diagnostic capabilities.

Double Shear Beam Load Cells

A double shear beam load cell is a type of load cell used for measuring force or weight in industrial weighing applications. The load cell consists of a metal body with two sets of parallel shear beams mounted inside, with the load applied to the center of the load cell. The double shear design provides a more stable and accurate measurement than a single shear beam load cell, as it reduces the effects of off-center loading and side forces. The load cell produces a signal proportional to the applied force or weight, which is then converted into a digital or analog output by a signal conditioner. Double shear beam load cells are commonly used in applications such as truck scales, platform scales, and tank weighing systems, where high accuracy and stability are required. They are also known for their durability and resistance to shock and vibration, making them suitable for use in harsh environments. All of Libra’s weighbridges are built with this type of load cell.

Donut Load Cells

Donut load cells are compact load cells that are ideal for applications where space is limited. They are commonly used in medical devices, robotics, and aerospace applications.

Dynamic weighing

weighing a moving object, such as a vehicle passing over a weighbridge or items on a conveyor belt, without requiring it to stop. Also known as Weigh-In-Motion (WIM).

Gross weight

the total weight of the vehicle, including its chassis, body, load, fuel, and driver.

Hopper scale

A weighing system that measures the weight of material in a hopper or tank. Hopper scales are common in agriculture, used to weigh bulk materials such as grain or seeds.

Hydraulic Load Cells

Hydraulic load cells use hydraulic pressure to measure force and are commonly used in applications where high accuracy is required, such as in calibration systems, materials testing machines, and force measurement devices.

Indicator

a device, also known as a weight terminal or controller, that receives the signal from the load cell(s), processes it, and displays the weight reading. Indicators can range from simple display units to complex controllers capable of data storage, communication, and process control.

IP Rating (Ingress Protection)

A standard classification system (e.g., IP67, IP68, IP69K) that indicates the degree of protection an enclosure provides against intrusion from solid objects (like dust) and liquids (like water). Essential for determining the suitability of weighing equipment for different operating environments.

Junction Box (Summing Box)

An enclosure used in weighing systems with multiple load cells (like weighbridges or large platform scales) to connect the individual load cell cables. It sums the electrical signals from the load cells and often includes components for trimming or balancing the output from each corner of the scale before sending a combined signal to the indicator.

Legal-for-trade

A weighing system that meets the stringent accuracy, reliability, and security requirements set by government regulations (like OIML or national standards) for use in commercial transactions where product is sold by weight. These scales must undergo specific testing and verification.

Legal Metrology

The practice and process of applying regulatory structure and enforcement to metrology (the science of measurement). In weighing, it ensures fairness and accuracy in trade, health, and safety applications through standards like OIML and national type approvals.

Load Cell

A load cell is a transducer that converts force or weight into a measurable electrical signal. It is the core sensing component in most electronic weighing systems. View the different types of load cells we offer here.

Net weight

the weight of the vehicle’s load only, calculated by subtracting the vehicle’s empty weight (Tare Weight) from its total weight (Gross Weight).

OIML

The International Organization of Legal Metrology (OIML) is an intergovernmental organization that develops model regulations, standards (known as Recommendations), and related documents for legal metrology authorities and industry. OIML Recommendations (e.g., R60 for load cells, R76 for non-automatic weighing instruments) provide internationally recognized technical requirements for weighing equipment used in legal-for-trade applications. Compliance ensures consistency and accuracy in global trade.

Overload

Applying a weight or force to a scale or load cell that exceeds its rated maximum capacity. This can cause inaccurate readings or permanent damage.

Overload protection

refers to features or mechanisms built into a weighing instrument or load cell designed to prevent damage from loads exceeding the rated capacity. This can be mechanical (physical stops) or electronic (software limits or warnings).

Process weighing

is a term used to describe the application of weighing technology within a manufacturing or production process for monitoring, controlling, or measuring materials. Examples include batching, dosing, filling, and level control by weight in tanks or silos.

Pneumatic Load Cells

Pneumatic load cells use air pressure to measure force and are commonly used in applications where the load cell must be isolated from the environment, such as in clean rooms or hazardous areas.

Pit Weighbridge

A type of weighbridge where the weighing platform is installed level with the surrounding ground surface within a concrete pit or foundation. This requires excavation and proper drainage but allows vehicles easy access from any direction.

Pitless Weighbridge (Surface Mount)

A type of weighbridge installed directly onto a prepared flat surface, typically concrete pads or strips. Vehicles access the platform via ramps. Installation is generally simpler and less costly than pit weighbridges, but they require more space for ramps.

Readability

The smallest increment in weight that the weighing instrument’s digital display shows (e.g., 0.1 kg, 5 kg). It indicates the level of detail in the displayed reading but does not necessarily reflect the scale’s accuracy.

Remote display

a secondary display unit that duplicates the weight reading shown on the main indicator but is located at a distance, often for visibility by the vehicle driver or other personnel.

Resolution

The smallest change in applied weight that a weighing instrument can detect and respond to. While often the same as readability in simpler scales, in high-precision systems, the internal resolution might be finer than the displayed readability.

RFID

Radio Frequency Identification is a technology using radio waves to automatically identify objects or people. In weighbridge systems, RFID tags fitted to vehicles and readers can automate vehicle identification, linking weighments to specific trucks for access control and data recording, especially in unmanned weighbridge operations.

Shear Beam Load Cells

A common type of load cell where the force is applied perpendicular to the beam’s axis, causing shear stress that is measured by strain gauges. Often used in platform scales, tank weighing, and process weighing applications. Single shear beam and double shear beam (as used in our weighbridges) are variants.

S-Type Load Cells

Named for their ‘S’ shape, these load cells are designed primarily for measuring tensile (pulling) forces but can often be used for compression as well. Common applications include suspended hopper weighing, crane scales, and material testing.

Stability

The condition where the weight reading on the indicator remains constant within specified limits, indicating the load is stationary and the measurement is reliable. Indicators often have a stability detector or symbol.

Static weighing

weighing an object, typically a vehicle, while it is completely stationary on the weighing platform. This generally provides the most accurate weight measurement compared to dynamic weighing.

Strain Gauge

A sensor whose electrical resistance varies in proportion to the amount of strain (deformation or stretching) applied to it. Strain gauges are the fundamental sensing element within most modern electronic load cells, detecting the minute bending or deformation of the load cell body under load. Also used in specialized applications like train weighing systems attached directly to rails.

Tare Weight

the weight of an empty vehicle, container, or vessel. This weight is measured or entered into the indicator so it can be subtracted from the Gross Weight to calculate the Net Weight of the contents or load.

Tolerance

The permissible limit or range of variation in a measurement or quantity. In weighing, tolerance defines the acceptable deviation of a scale’s reading from the true weight (as determined by standard weights during calibration or verification).

Traceability

The property of a measurement result whereby it can be related to stated references, usually national or international standards, through an unbroken chain of comparisons all having stated uncertainties. Essential for ensuring that calibrations are valid and meaningful.

Train Balancing

The process of distributing the load weight evenly across the wagons or bogies of a train to ensure stability, safety, and efficient operation, preventing excessive wear on tracks and wheels.

UKCA Marking

The UK Conformity Assessed marking is the product marking used for goods being placed on the market in Great Britain (England, Wales, and Scotland). It covers most goods which previously required the CE marking before the UK left the European Union.

Verification

A formal inspection and testing procedure performed by authorized personnel or bodies to confirm that a weighing instrument meets all legal requirements (e.g., accuracy, construction, markings) for its intended use, particularly for ‘Legal-for-Trade’ applications. Verified scales are often sealed to prevent tampering.

Weighbridge

A large, robust platform scale designed primarily for weighing road vehicles like trucks and lorries, although versions exist for rail vehicles. They are typically installed permanently and form a critical part of logistics, resource management, and trade operations. See our weighbridge products.

Weighing platform

the physical structure of the scale or weighbridge onto which the load (e.g., a vehicle) is placed to be weighed. Also referred to as the deck or bridge.

Weighing software

computer programs designed to interface with weighing indicators or controllers. This software enhances functionality by enabling data storage, transaction management, reporting, integration with other business systems (like accounting or ERP), and control of peripheral devices (like barriers, traffic lights, ANPR cameras). See our software solutions.

WIM (Weigh-In-Motion)

Technology used to measure the weight of vehicles (road or rail) as they travel over measurement sensors at normal or reduced speeds, without requiring them to stop. WIM systems are used for screening, data collection, and enforcement purposes. For trains, see train weighers. For road vehicles, see axle weighers which can sometimes operate in a slow-speed WIM mode.

Zero / Zeroing

The operation of setting the weight indicator to display zero. This is typically done before placing a load on the scale or after placing an empty container (tare) to ensure subsequent readings represent the net weight of the product being weighed. Most scales have a zero function to compensate for drift or debris on the platform.