Industrial Weighing

Industrial weighing is a critical component in manufacturing, logistics, and process automation, providing accurate mass measurement necessary for quality assurance, regulatory compliance, and process optimization. It is employed in bulk material handling, automated packaging, dosing, batching, and inventory control, ensuring precise weight measurement under varying operational conditions.

Industries such as food processing, pharmaceuticals, chemicals, mining, and heavy manufacturing require high-accuracy weighing solutions to maintain product consistency, minimize material losses, and meet stringent industry standards. Industrial weighing systems must integrate seamlessly with automation platforms, ensuring real-time data acquisition, process monitoring, and control.

A typical industrial weighing system consists of load cells, mounting hardware, and data acquisition electronics. Load cells convert mechanical force into an electrical signal, while mounting kits ensure mechanical stability and force distribution. These components are designed to work in harsh industrial environments, maintaining measurement accuracy despite mechanical vibrations, temperature fluctuations, and external disturbances.

 

Load Cells: The Foundation of Force Measurement

A load cell fundamentally converts a force—tension, compression, or shear—into a measurable electrical output, typically a change in voltage. This electrical signal's magnitude is directly proportional to the applied force, enabling precise weight determination. Load cells are the cornerstone of various applications, including industrial scales, force testing machines, process control systems, robotics, automation, and even medical devices. They provide the crucial link between mechanical forces and electronic measurement systems.

 

Weigh Cells: Specialized Load Cells for Weighing

While often used interchangeably, the terms "load cell" and "weigh cell" can have slightly different meanings in certain contexts. Generally, a load cell broadly describes any transducer that converts force into an electrical signal. A weigh cell is a load cell specifically optimized for high-precision weight measurement, typically found in automated weighing systems such as checkweighers, dosing machines, and high-speed industrial scales.

 

Weigh Cells

Weigh cells are specialized load cells designed to meet the stringent requirements of weighing applications. They are engineered to provide exceptional accuracy, repeatability, and stability under a range of environmental conditions. These characteristics are essential for reliable weight measurement in platform scales, tank and hopper weighing systems, checkweighing equipment, filling and dosing machinery, and conveyor scales. The design and materials used in weigh cells are carefully chosen to minimize the influence of external factors on the weight measurement. They are designed to be very stiff and have very little deflection under load.

How Load Cells and Weigh Cells Work:
Strain Gauge Technology and the Wheatstone Bridge

Load cells and weigh cells operate based on strain gauge technology, which converts mechanical force into an electrical signal for precise weight measurement. A strain gauge is a sensor that detects the minute deformation (strain) in a load cell’s structure when force is applied. Strain gauges consist of thin resistive foil elements bonded to specific points on the load cell where mechanical strain occurs under load. These elements change their electrical resistance when stretched or compressed, providing the basis for weight measurement.

Strain gauge-based load cells are widely used in industries such as industrial automation, aerospace, automotive, medical equipment, and process control due to their high precision, durability, and adaptability to harsh environments. Their accuracy can range from ±0.1% to ±0.005%, making them suitable for even the most demanding applications.

 

 

Advanced load cells incorporate multiple strain gauges at strategic locations to compensate for temperature changes and mechanical inconsistencies. Some high-precision models use six or more strain gauges instead of the standard four, further refining accuracy and reducing noise.

The manufacturing process of load cells demands micron-level machining accuracy to ensure the body is perfectly designed to distribute force predictably. Any imperfection in machining or strain gauge placement can cause measurement errors.

Wheatstone Bridge Circuit: Enhancing Accuracy in Load Measurement

Since the resistance changes caused by strain gauges are extremely small, they require a highly sensitive electrical circuit for precise detection. Load cells achieve this by using a Wheatstone bridge circuit, which magnifies these small resistance variations and converts them into a measurable voltage signal.

Configuration of the Wheatstone Bridge

A typical full-bridge Wheatstone circuit consists of four strain gauges arranged in a balanced configuration. Two strain gauges experience tension (increasing resistance), while the other two experience compression (decreasing resistance). This arrangement ensures temperature compensation and cancels out external noise, leading to highly stable measurements.

Some load cells use a half-bridge or quarter-bridge Wheatstone circuit, depending on the required accuracy and application.

 

Load Cell Wiring and Signal Transmission

Load cells generally have four or six wires:

• Excitation wires (+EXC and -EXC): Provide voltage to the Wheatstone bridge.
• Signal wires (+SIG and -SIG): Transmit the small voltage output from the bridge to the amplifier.
• Sense wires (+SEN and -SEN) (in six-wire load cells): Compensate for voltage drops in long cable runs to maintain precision.

The load cell's excitation voltage typically ranges from 3V to 15V DC, depending on the application. The output signal—usually between 0 to 50 mV—is expressed in millivolts per volt (mV/V), indicating how many millivolts the load cell generates per applied excitation voltage.

Signal Processing for Accurate Weight Measurement

Since the Wheatstone bridge produces a very low-voltage signal, it must be amplified and converted into a digital format for further processing. Modern weighing systems integrate:

• High-resolution Analog-to-Digital Converters (ADCs): Transform the amplified signal into a digital weight value.
• Digital Filtering & Temperature Compensation: Eliminate unwanted noise and maintain accuracy across different environmental conditions.
• Industrial Protocol Integration: Communication interfaces such as Modbus, EtherNet/IP, CANopen, and Profibus ensure seamless integration into automation systems.

By leveraging strain gauge technology, the Wheatstone bridge circuit, and advanced signal processing, load cells and weigh cells deliver highly accurate and reliable force measurements across a wide range of industrial applications.

Weigh Cell Types and Technologies

Several types of weigh cells are available, each designed for specific applications and load ranges. Here's a closer look at some common types and the principles behind them:

• Single Point Load Cells: Single point weigh cells are designed to measure weight at a single location while compensating for off-center loads. They are the most commonly used weigh cells in bench scales, retail scales, and packaging machines due to their high accuracy and ability to handle unevenly distributed loads.
• Shear Beam and Bending Beam Weigh Cells: These weigh cells measure force through shear or bending stress applied to the structure. They offer higher stability and are commonly used in industrial weighing applications such as tank weighing, hoppers, and conveyor
• Compression Weigh Cells: Compression weigh cells are designed to measure weight under direct vertical force. These are primarily used for high-capacity weighing applications where stability and load distribution are critical. Compression load cells are commonly found in truck scales, railroad scales, silo weighing, and other high-capacity applications.
• Tension: Tension weigh cells are designed to measure pulling force rather than compression. They are commonly used in suspended weighing applications where the object being weighed is hanging rather than placed on a platform. They are commonly used in hanging scales, crane scales, and tensile testing machines in industrial applications.

Browse Models

 

Weighing Electronics: The Brain of the System

Weighing electronics are the critical link between the raw analog signal generated by load cells and the digital world of automation and data management. These devices, often called weighing controllers or transmitters, perform the essential tasks of signal conditioning, processing, and communication, transforming a minute voltage change into usable weight data and enabling sophisticated control functionalities. Their primary role is to convert the electrical signals produced by the weigh cells into a meaningful weight value. They also play a crucial role in ensuring that the weight data is accurate, reliable, and readily available for use in various industrial processes.

 The core functions they provide are:

• Signal Conditioning: The output signal from a load cell is typically very small (in the millivolt range) and susceptible to electrical noise. Weighing electronics amplify this weak signal to a more manageable level and employ sophisticated filtering techniques to remove unwanted noise, ensuring a clean and stable signal for accurate measurement.
• Analog-to-Digital Conversion: The amplified analog signal is converted into a digital format using high-resolution analog-to-digital converters (ADCs). This digital representation allows for precise weight calculations and facilitates communication with other digital systems.
• Weight Calculation: The digital signal is processed using calibration factors to determine the actual weight. Calibration involves correlating the digital output to known weights, establishing a precise relationship between the electrical signal and the applied load.
• Display: The calculated weight is displayed on a digital readout, providing a clear and user-friendly representation of the measurement.
• Control Functions: Many weighing controllers include advanced control features such as setpoints, batching control, checkweighing functions, and more. These features automate weighing processes and integrate them into larger control systems.
• Communication: Modern weighing electronics are equipped with a variety of communication interfaces, enabling them to seamlessly integrate into automated systems. These interfaces include:
  • Serial Communication: RS232, RS485
  • Industrial Fieldbuses: CANopen, Modbus RTU, Profibus DP
  • Ethernet-Based Protocols: Modbus TCP, Ethernet/IP, PROFINET, EtherCAT

These protocols allow the weighing electronics to communicate with PLCs, computers, and other industrial devices, transmitting weight data, receiving commands, and participating in complex control sequences.

Advanced Weighing Control with Intelligent Electronics

Intelligent weighing controllers, such as the eNod4 series, represent a significant advancement in weighing technology. They offer a high degree of integration, combining multiple functions into a single device. This integration simplifies system design, reduces wiring complexity, and enhances overall performance.

 

 

These modules offer:

High-Speed Processing: Advanced weighing controllers like the eNod4 series provide rapid data acquisition and processing capabilities. For example, they may offer internal measurement rates of up to 1,600 measurements per second and fast output data rates, which are crucial for dynamic weighing applications such as checkweighing or high-speed filling. Some models, like the eNod4-T, offer internal resolution of up to ±500,000 divisions.

Integrated Application Functions: These controllers are often equipped with pre-programmed application functions tailored for specific weighing tasks, simplifying configuration and reducing development time. Examples include:

 

• Continuous Weighing: For applications like silo or hopper weighing, the eNod4-T provides real-time weight monitoring and control.
  • It offers physical or theoretical calibration.
  • It can manage gravity correction.
  • It offers linearization in multiple segments.
  • It manages measurement scaling and unit management.
  • It manages zero, zero tracking, tare, and stability control.

 

• Checkweighing/Grading: It is is designed for dynamic weighing applications, where items are weighed while moving on a conveyor. The eNod4-C is specifically optimized for sorting and grading applications, ensuring fast and precise weight verification in high-speed production lines.
  The eNod4-C detects weight through level-based or external triggering, calculates the weight automatically, and applies statistical functions to monitor trends. Non-conforming products are managed through automated ejection control, ensuring consistent quality on high-speed production lines.
  • It can manage 1 or 2 digital inputs.
  • It can calculate the weight automatically and use statistical functions.

 

 

 

• Batch Dosing/Filling: For precise dispensing of materials by filling or unloading, ensuring accuracy in batch processing and packaging applications. The eNod4-D operates in single, dual, or three-speed dosing modes, automatically adjusting inflight corrections to maintain target weight. It controls emptying, reloading, and flow rate monitoring, detecting dosing errors and ensuring consistent material distribution.
  • It can manage dosing by filling or unloading.
  • It offers 1, 2, or 3 feed rates.
  • It can manage automatic inflight correction.

 

 

• Belt Weighing/Continuous Totalization: For monitoring and controlling material flow on conveyor belts, calculating real-time flow rates and totalized weight. The eNod4-B integrates weight and speed measurements to ensure precise continuous totalization. Its PID-based flow regulation adjusts belt speed or feed rate, optimizing throughput.
  • It manages weight integration per unit of length.
  • It manages flow rate and continuous total weight.
  • It offers an accumulated pulse output function.
  • It can manage load cycles with targeted total.
  • It can manage target flow.

 

• Loss-in-Weight Feeding: It regulates continuous material dispensing by monitoring weight reduction over time. The eNod4-F maintains a target flow rate using a PID controller, dynamically adjusting feeder operation. Automatic refilling management ensures uninterrupted material flow, seamlessly alternating between gravimetric dosing and refilling phases.
  • It offers loss-in-weight feeding functionality.
  • It can manage target flow and target total.
  • It offers flow regulation by PID controller.
  • It can manage alternating gravimetric dosing and refilling phases.

 

Advanced Digital Filtering: To mitigate the effects of vibration and mechanical noise, which can significantly impact weighing accuracy, intelligent controllers incorporate sophisticated digital filtering algorithms. These filters can be adjusted and optimized to suit the specific application and environment. For instance, the eNod4 series offers up to 4 levels of digital filtering.

Self-Adjusting Control: Some advanced controllers, like certain eNod4 models, feature self-learning algorithms that can automatically adjust control parameters (e.g., PID settings) to optimize performance in dynamic weighing applications. For example, the eNod4-F offers a function of automatic adjustment of PID parameters by self-learning.

Diagnostics: Many intelligent controllers have built-in diagnostic features, such as load cell failure detection, which can alert operators to potential problems and help prevent inaccurate measurements.

 

 

Mounting Accessories for Industrial Weighing

Mounting accessories are essential for ensuring the accuracy, stability, and longevity of industrial weighing systems. Load cells are highly sensitive to external forces, such as vibrations, misalignment, and thermal expansion, which can affect measurement accuracy. Proper mounting solutions mitigate these influences, providing secure installation and reliable weight readings in applications such as silos, tanks, hoppers, and conveyor systems.

 

 

The Role of Mounting Kits in Weighing Systems

Mounting kits are designed to mechanically secure load cells while allowing them to perform precise weight measurement. They compensate for external forces and environmental conditions, such as side loads, thermal expansion, and mechanical vibrations, which can interfere with the accuracy of the load cell's readings. In dynamic applications, such as mixing tanks or conveyor-based systems, specialized mounting kits provide additional stabilization.

For large structures like silos and tanks, anti-lift systems and lateral stop mechanisms prevent movement and structural shifts that could affect weighing accuracy. Some mounting kits also include integrated jacking systems, which allow for easier installation and maintenance of load cells without requiring complete system shutdowns.

Weighing Solutions for Different Applications

Silo and Tank Weighing

For high-capacity weighing applications, such as silos, tanks, and industrial storage vessels, mounting kits are designed to handle heavy loads and structural shifts. These systems incorporate built-in lift-off prevention and stabilization devices, ensuring that the tank remains securely positioned. The SILOSAFE-R and SILOSAFE-R EVO mounting kits are designed for high-capacity tank and silo weighing, featuring anti-lift systems and cross stoppers to maintain structural integrity.

In environments with dynamic forces, STABICAN provides additional lateral stability, while RH10X mounting cups ensure proper weight distribution.

 

For silo and hopper weighing applications, SILOKIT-R is an ideal solution when paired with the R10X stainless steel load cell. This combination provides stabilization and precise weight measurement by ensuring that the load is applied perpendicularly to the measurement surface, minimizing inaccuracies caused by misalignment. The SILOKIT-R also integrates heavy-duty stoppers, which prevent excessive movement due to structural shifts, vibrations, or material flow.

 

 

Hopper and Blender Weighing

Hopper weighing requires mounting accessories that provide stability while allowing for controlled movement, as hoppers are frequently emptied and refilled. The STABIFLEX EVO mounting kit is designed to absorb lateral forces and minimize structural stress, ensuring precise weight measurement even under dynamic conditions.

ISOFLEX incorporates vibration damping elastomers, making it ideal for applications where mechanical disturbances may impact readings. RUBBERKIT-FX is another solution that provides shock absorption and misalignment compensation, maintaining stable weight readings in active industrial environments.

 

 

 

Dynamic Weighing and Conveyor-Based Weighing

Weighing in motion-based applications, such as belt weighers, conveyor scales, and checkweighing systems, requires specialized mounting solutions that compensate for continuous force variations and mechanical vibrations while ensuring reliable weight measurement.

For dynamic weighing systems, the RUBBERKIT-FX mounting kit, designed for F60X load cells, features a rubberized upper plate to absorb vibrations and compensate for misalignment, ensuring stable weight readings even under fluctuating loads. This mounting system is commonly used in conveyor-based weighing and automated material handling applications, where constant force variations require effective dampening.

 

 

Hanging Hopper Weighing

Suspended hoppers require tension-based load measurement, meaning that mounting solutions must allow for accurate weight transmission while compensating for angular movement and oscillations.

For hanging hopper weighing, ROD ENDS (ZF / ZA30X) mounting kits provide rod-end ball joint stabilization, allowing for accurate tension force measurement in suspended weighing applications. These solutions are widely used in bulk ingredient dosing, overhead conveyor weighing, and crane scale systems, where maintaining measurement precision despite constant movement is critical.

 

 

Horizontal Tank Weighing

For liquid tanks, where precise weight measurement is not always necessary, a combination of fixed bearings and weighing modules can be used to maintain structural stability while allowing weight measurement on select load cells.

In these applications, fixed bearing systems support part of the tank’s weight, while two active load cells handle the measurement. This solution is typically implemented in level monitoring applications, where weight is used to estimate liquid volume rather than provide highly precise mass measurements.

 

Applications of Weighing Systems in Logistics

 

1. Overload Detection for Automated Stacker Cranes

Ensuring safe material handling and preventing overloading during storage and retrieval operations.

• Load Measurement: Accurate load detection using load pins (M16).
• Alarm Management: Monitored via the CPJ analog transmitter, ensuring safety and compliance.

2. On-the-fly Weighing on Conveyors

Real-time weight calculation during material movement, optimizing the conveyor system without slowing down operations.

• Weight Calculation: A Bending Beam Load Cell (F60X) integrated with the eNod4-C controller for precise on-the-fly weighing.
• Accurate Detection: Detection by cell or weight level, with digital signal filtering for enhanced weighing precision.

3. Weighing on Automatic Palletizers

Streamlining the packaging process by integrating weighing systems into palletizer conveyors.

• Weighing System: Built into the palletizer conveyor to resist lateral and longitudinal forces, ensuring seamless operation.

4. Weight Control on AMR/AGV or Picking Carts

Ensuring accuracy and balance during order fulfillment and material transport with automated guided vehicles (AGVs) or picking carts.

• Single Point Load Cells: For accurate weight measurement or center of gravity control.
• Seamless Data Transmission: Weighing data transmitted over the automation network for real-time monitoring and adjustments.

 

Industrial weighing plays a crucial role in optimizing manufacturing, logistics, and automation processes, ensuring precise measurements that drive efficiency, regulatory compliance, and product consistency. With advanced load cells, intelligent weighing electronics, and specialized mounting accessories, businesses can achieve higher accuracy, reliability, and integration into automated systems.

Choosing the right weighing technology and implementation strategy is essential for maximizing productivity, reducing waste, and ensuring seamless process control. Whether for high-speed production lines, heavy-duty silo weighing, or dynamic conveyor-based applications, our solutions are engineered to meet the highest industry standards.

Contact Us for Tailored Weighing Solutions

For more information on how our industrial weighing solutions can enhance your processes, or to discuss a customized weighing system for your application, contact our team of experts. We are here to help you integrate the most efficient and precise weighing technology into your operations.