What is a Load Cell?
A load cell is a transducer or sensor that is used to convert a mechanical force or load into an electrical signal. It is a critical component in various applications where the measurement of force, weight, or tension is required. Load cells are commonly used in industrial, scientific, and commercial settings to obtain accurate and reliable measurements of forces or loads.
Here are the key components and functions of a load cell:
Strain Gauges: Load cells typically contain one or more strain gauges, which are thin, wire-like devices that are bonded or attached to a structural element within the load cell. Strain gauges are designed to deform when subjected to mechanical force, and this deformation results in a change in electrical resistance.
Wheatstone Bridge Circuit: Strain gauges are configured in a Wheatstone bridge circuit, which is an electrical circuit that can detect small changes in resistance. When force is applied to the load cell, the strain gauges experience deformation, causing a change in resistance. This change in resistance leads to an imbalance in the Wheatstone bridge, generating an electrical output signal.
Output Signal: The electrical output signal produced by the load cell is typically very low in magnitude, often in the millivolt (mV) range. This signal is proportional to the applied force or load and can be further processed and amplified to obtain meaningful measurements.
Calibration: Load cells must be calibrated to ensure accurate and consistent measurements. Calibration involves applying known forces to the load cell and recording the corresponding output signals. This calibration data is used to establish a relationship between the applied force and the output signal.
Types of Load Cells: There are various types of load cells, each designed for specific applications and load measurement requirements. Common types include:
Strain Gauge Load Cells: These load cells use strain gauges to measure the deformation caused by the applied force. They are suitable for a wide range of applications and are available in various configurations, including bending beam, shear beam, and single-point designs.
Compression Load Cells: Designed to measure forces that compress the load cell along its central axis, compression load cells are often used in applications like platform scales and industrial weighing.
Tension Load Cells: These load cells are designed to measure forces that pull or stretch the load cell, making them suitable for applications like crane scales and tensile testing.
Shear Beam Load Cells: Shear beam load cells are commonly used in industrial scales and conveyor systems to measure forces applied parallel to the load cell's mounting surface.
Bending Beam Load Cells: Bending beam load cells are versatile and used in applications such as floor scales and batching systems.
S-Type Load Cells: Shaped like the letter "S," these load cells can be used for both tension and compression measurements.
Load cells find applications in various industries, including manufacturing, aerospace, automotive, healthcare, agriculture, and more. They are crucial for tasks such as weight measurement, force monitoring, quality control, and process automation, contributing to increased accuracy, efficiency, and safety in numerous processes and systems..
How does a Load Cell work?
A load cell works on the principle of converting an applied mechanical force or load into an electrical signal. It accomplishes this by utilizing one or more strain gauges, which are devices that change their electrical resistance in response to mechanical deformation. Here's a step-by-step explanation of how a load cell works:
Strain Gauges: Load cells typically incorporate one or more strain gauges, which are small sensors made of thin wires or foil elements. These strain gauges are bonded or attached to a structural element within the load cell, such as a beam or diaphragm.
Wheatstone Bridge Circuit: The strain gauges are arranged in a Wheatstone bridge circuit, which is an electrical circuit designed to measure small changes in resistance. The Wheatstone bridge consists of four resistors, with the strain gauges forming two of them. The other two resistors are typically fixed or have a known resistance value.
Zero Load State: When there is no load applied to the load cell (the "zero load" or "no force" state), the strain gauges are in their initial, undeformed condition, and their resistance values are stable.
Application of Load: When a mechanical force or load is applied to the load cell, it causes deformation or strain in the structural element to which the strain gauges are attached. This deformation results in a change in the resistance of the strain gauges.
Imbalance in the Wheatstone Bridge: The change in resistance of the strain gauges creates an imbalance in the Wheatstone bridge circuit. As a result, there is an output voltage or electrical signal generated across the bridge's output terminals. The magnitude and polarity of this output signal are proportional to the applied force or load.
Signal Amplification and Conditioning: The electrical output signal produced by the Wheatstone bridge is typically very low in magnitude, often in the millivolt (mV) range. To obtain useful measurements, the signal is amplified and conditioned using signal conditioning circuits. This may involve amplifying the signal, filtering out noise, and compensating for temperature variations.
Calibration: Load cells are calibrated to establish a linear relationship between the applied force and the output signal. During calibration, known forces are applied to the load cell, and the corresponding output signals are recorded. This calibration data is used to create calibration curves or equations for accurate force measurement.
Output Signal: The amplified and conditioned electrical signal is then available for measurement, display, recording, or control purposes. Depending on the application, load cell signals can be analog (voltage or current) or digital.
Accuracy and Resolution: The accuracy and resolution of a load cell depend on factors such as the quality of the strain gauges, the design of the load cell, the calibration process, and the signal conditioning. High-quality load cells are capable of providing accurate and precise measurements.
Load cells come in various types, including compression load cells, tension load cells, shear beam load cells, and more, each designed for specific force measurement applications. They are widely used in industries such as manufacturing, automotive, aerospace, healthcare, and research to measure forces, weights, and loads accurately and reliably.
Load Cell Choices
How to choose the correct Load Cell and compatible instrument for your load or force measurement application?
Our application sales engineers do this day in and out, with years of experience so please don’t hesitate to give us a call to help you though this process, that’s what we are here for. But it all comes down to your budget, your application, what stage your application is in, and how quickly you need your load cell system.
Let me start with a few easy applications and I will follow it by a layout of things you should consider in your load cell selection process.
If you need to perform a quick one time test to verify a load or force on a component or to prove an application, you might choose an inexpensive load beam load cell with a precision power supply and a voltmeter. We can help.
If you’re designing a Test machine you would choose a load cell based upon the overall system accuracy. Is the measurement static or dynamic? Do you require a digital display or just an amplifier signal conditioner module for a data acquisition system? We can help.
If your application is on a race car suspension system recording real time data while testing the car on an actual race track, like the Cornell racing team in one of our featured videos, you would need a load cell that could perform in a dynamic application and be able to handle extraneous loads like our MLP series load cell did. We double the normal load capacity of the load cell (which is a good rule of thumb in dynamic loading applications) and still exceeded the accuracy they required. We supplied our TM0-1 amplifier signal conditioner module that sent high speed data to their on board data acquisition system. We also designed a custom load pin load cell to measure the torque on the drive train. In some applications going with a custom load cell makes more sense.
National Geographic had an application on one of their super human strength episodes where they needed to measure the force of a strong man pulling a Semi tractor trailer (featured in our video gallery) that they were filming the next day. We choose the HSW-20k load cell with the smart plug and play option (also known as our Cal-Teds option) because of the accuracy and the ease of placing it in the application. We supplied our smart plug and play DPM-3 load cell meter with an analog output option that sent real time data to their data acquisition system that they were pushing in a cart alongside of the test. Having the Cal-Teds option on the load cell allowed the load cell and the smart plug and play DPM-3 meter to automatically perform a system calibration by just plugging them together (meter reads the EPPROM chip in the Cal-Teds option that populates an IEEE 1451.4 template 33 calibrating the system instantly). We generally don’t recommend pushing a cart alongside of a test, but this was already taking place for other equipment. This was a very inexpensive load cell system that allowed them to film the next day as planned.
Below is a list of things to consider when selecting a load cell for your load / force measurement requirement:
Step 1
Price and availability are normally the first two things to consider. If you’re on a limited budget or need something the next day this may narrow your selection. However Transducer Techniques does offer educational discounts and we stock our standard products ready for next day shipping.
Step 2
Define how you want to conduct the measurement and how you will apply the load. Will your loading be static or dynamic? A dynamic application usually requires a load cell with a higher frequency response (a good rule of thumb is the lower the load cell deflection the high the frequency response). Will you be loading the load cell in-line or require a load cell that can handle extraneous loads? Will you be measuring bending, tension or compression or both, multi-axis such as thrust and torque?
Step 3
Define how this load cell will be mounted in your application. Do you require male or female threads or a flange mount? Do you need a through hole or compression load washer load cell that allows a structure to pass through the load cell?
Step 4
Define the environment in which the load cell is intended to be used in (laboratory, warehouse, outdoors, underwater). For extended outdoor use or in a marine environment or for underwater use, we recommend a hermetically seal load cell.
Step 5
Define the overall accuracy, output, bridge resistance, nonlinearity, hysteresis, nonrepeatability, frequency response.
Step 6
Define if there are any special options required, such as, connectors, addition cable lengths, high temperature,or if Cal-Teds (plug and play smart load cell option) is required.
Step 7
Define if load cell instrumentation is required. From a precision power supply, to an amplifier signal conditioner module, to a digital display with alarms, analog output or data logging, we have economical solutions for your load cell instrument requirements.
In summary, for someone using a load cell for the first time this can be overwhelming. But this is what we enjoy doing and we are always here for you. Please allow us to help you select the right load cell from installation, to setup, we will be here to assist you every step of the way.
TBS Series Force sensor Applications.
The Transducer Techniques TBS Series thin beam force sensors, known for their sensitivity and compact design, are widely used in various industries and applications that require precise small load measurements. These force sensors, available in eight capacity ranges from 0 to 0.25 lbs. to 0 to 40 lbs., are designed to measure a wide range of parameters in diverse fields. Here are some specific applications where the TBS Series thin beam force sensors are commonly used:
1. Medical Instrumentation: TBS Series force sensors are employed in medical devices and instruments for applications such as force sensing in surgical instruments, infusion pumps, and medical testing equipment.
2. Home Appliances: These force sensors find applications in home appliances, including washing machines, dishwashers, and appliances with touch-sensitive controls, ensuring precise load measurements and user interactions.
3. Process Control: TBS Series force sensors are integrated into process control systems to monitor and control small forces and loads in manufacturing and industrial processes. They contribute to process efficiency and quality control.
4. Robotics: In robotics, these force sensors are used to measure forces and loads in robotic grippers, end-effectors, and arms. This information helps robots interact with objects and perform tasks more accurately.
5. Automotive: Automotive manufacturers and suppliers use TBS Series force sensors in various applications, including automotive safety systems, seatbelt tensioning, and airbag deployment, to ensure accurate load measurements and safety.
6. Consumer Electronics: TBS Series sensors are used in consumer electronics devices, such as touchscreens and input devices, to provide precise force sensing capabilities for user interactions.
7. Industrial Automation: In industrial automation and manufacturing, these sensors are integrated into machinery and equipment for force monitoring and control in applications like assembly, material handling, and testing.
8. Quality Control: Industries with stringent quality control requirements, such as electronics manufacturing, utilize TBS Series force sensors for quality testing of small components and products.
9. Aerospace: The aerospace industry uses these force sensors for various applications, including load measurement in small components and test setups for aircraft and spacecraft.
10. Research and Development: Engineers and researchers use TBS Series force sensors during product development and testing to measure and analyze small forces and loads in various experimental setups.
11. Haptic Feedback: TBS Series sensors can be integrated into devices that provide haptic feedback, enhancing the user experience in virtual reality applications and touch-sensitive devices.
The Transducer Techniques TBS Series thin beam force sensors offer exceptional stability and reliability, making them ideal for small load measurement applications across a wide range of industries. Their sensitivity and accuracy contribute to improved product quality, safety, and efficiency in diverse applications.
EBB Series Force sensor Applications.
The Transducer Techniques EBB Series economical low-capacity bending beam force sensors are versatile and cost-effective solutions for various industrial and OEM (Original Equipment Manufacturer) applications that require force measurement and weighing. These sensors are made of an aluminum alloy and are available in 1, 2, 5, and 10-kilogram ranges. Here are some specific applications where the EBB Series bending beam force sensors are commonly used:
1. Industrial Weighing Systems: EBB Series sensors are frequently integrated into industrial weighing systems, such as bench scales, platform scales, and hopper scales, to measure the weight of materials, products, or components accurately.
2. Check Weighers: In check-weighing systems used in food processing, pharmaceuticals, and manufacturing, EBB Series sensors ensure that products meet weight specifications, contributing to quality control and compliance with regulations.
3. Conveyor Scales: Industries employ EBB Series sensors in conveyor scales to continuously monitor and record the weight of materials or products as they move along a conveyor belt. This is essential for inventory management and process control.
4. Filling and Packaging Machines: In the food and beverage industry, EBB Series sensors are used in filling and packaging machines to measure and control the amount of product dispensed into containers, ensuring consistent filling and packaging.
5. Material Handling Equipment: Manufacturers of material handling equipment, such as lift trucks, pallet jacks, and conveyor systems, use EBB Series sensors to determine load weight for safe and efficient handling and transportation.
6. Tank and Silo Weighing: EBB Series sensors are integrated into tanks and silos to measure the weight of stored materials, helping manage inventory levels and prevent overfilling or underfilling.
7. Force Measurement in Test Rigs: These sensors find applications in test rigs and equipment used for various tests, including component fatigue testing, material strength testing, and load testing of small structures.
8. Laboratory Balances: EBB Series sensors are used in laboratory balances and scales for precise weight measurement in research, pharmaceutical, and scientific laboratories.
9. Medical Devices: In the medical field, these sensors are utilized in medical devices and equipment that require accurate force measurement, such as infusion pumps and diagnostic devices.
10. Custom Machinery: OEMs integrate EBB Series sensors into custom-built machinery and equipment designed for specialized force measurement applications in industries such as manufacturing and automation.
11. Quality Control: Industries across the board use EBB Series sensors for quality control purposes, ensuring that products meet weight and force specifications.
12. Automotive Testing: Automotive manufacturers use EBB Series sensors in testing and validation processes, including component testing and quality control of automotive parts.
The Transducer Techniques EBB Series bending beam force sensors provide reliable and cost-effective solutions for a wide range of industrial and OEM applications where precise force measurement and weighing are essential. Their durability, accuracy, and versatility make them valuable tools for improving product quality and process efficiency.
LSP Series Force sensor Applications.
The Transducer Techniques LSP Series low-capacity, low-cost, and highly accurate single-point bending beam force sensor is designed for various OEM (Original Equipment Manufacturer) force measurement applications, particularly in the field of weighing and scales. Here are some specific applications where the LSP Series single-point bending beam force sensor is commonly used:
1. Electronic Scales: LSP Series sensors are frequently integrated into electronic scales, including kitchen scales, bathroom scales, postal scales, and industrial weighing scales. They provide accurate weight measurement for various applications.
2. Weighing Machines: In addition to scales, LSP Series sensors find applications in various types of weighing machines used in factories, warehouses, and industrial settings, ensuring precise and reliable weight measurement.
3. Retail Point of Sale (POS) Systems: Retailers use LSP Series sensors in POS systems integrated into checkout counters and cash registers. These sensors contribute to accurate pricing and inventory control.
4. Postal and Shipping Systems: Postal and courier services employ LSP Series sensors in postage meters and parcel weighing machines to determine shipping costs based on weight accurately.
5. Food Processing and Packaging: The food industry uses LSP Series sensors in packaging machines to measure the weight of food products accurately, ensuring consistency in portioning and packaging.
6. Pharmaceutical Manufacturing: Pharmaceutical companies utilize LSP Series sensors in manufacturing equipment for accurately measuring ingredients and controlling the quality of pharmaceutical products.
7. Laboratory Balances: LSP Series sensors are integrated into laboratory balances and precision scales used in scientific research, analytical chemistry, and pharmaceutical laboratories.
8. Material Testing: These sensors find applications in material testing equipment, such as compression testers and tension testers, to measure the force applied to materials during testing processes.
9. Customized Scales and Weighing Systems: OEMs integrate LSP Series sensors into custom-designed scales and weighing systems used in specialized applications, including industrial automation and material handling.
10. Force Measurement in Production Processes: Industries across various sectors use LSP Series sensors in production processes to monitor and control forces in manufacturing and assembly operations, ensuring quality and consistency.
11. Quality Control: LSP Series sensors are employed in quality control processes, allowing manufacturers to verify the weight and force specifications of products before they are shipped to customers.
12. Load Monitoring: LSP Series sensors are used in load monitoring systems, such as load cells in elevators and conveyor systems, to ensure safe and efficient operation.
The Transducer Techniques LSP Series single-point bending beam force sensor's combination of low cost, high accuracy, and resistance to eccentric loading makes it an ideal choice for OEMs and various industries requiring precise force and weight measurements. These sensors contribute to improved product quality, efficiency, and cost-effectiveness in a wide range of applications.d OEM applications where precise force measurement and weighing are essential. Their durability, accuracy, and versatility make them valuable tools for improving product quality and process efficiency.
ESP Series Force sensor Applications.
The Transducer Techniques ESP Series, characterized by its cost-effectiveness, high accuracy, and single-point bending beam design, is well-suited for various OEM (Original Equipment Manufacturer) force measurement applications, particularly those involving electronic scales and weighing machines. Here are specific applications where the ESP Series single-point bending beam force sensor is commonly used:
Electronic Scales: ESP Series sensors are frequently integrated into electronic scales of various types, including kitchen scales, bathroom scales, and industrial scales, ensuring accurate and reliable weight measurement for consumers and industries.
Weighing Machines: Industries that rely on precise weight measurement, such as manufacturing, logistics, and agriculture, use ESP Series sensors in various weighing machines for inventory management and quality control.
Retail Point of Sale (POS) Systems: In retail environments, ESP Series sensors are integrated into POS systems, allowing for accurate and efficient checkout processes by providing precise weight measurements for pricing and inventory control.
Parcel and Package Weighing: Parcel and package weighing systems, such as those used by courier and postal services, utilize ESP Series sensors to determine shipping costs based on accurate weight measurements.
Food Processing and Packaging: The food industry employs ESP Series sensors in packaging machines to ensure precise portioning and packaging of food products, maintaining consistency and compliance with quality standards.
Pharmaceutical Manufacturing: Pharmaceutical companies use ESP Series sensors in various stages of manufacturing to measure and control the weight of ingredients and products, ensuring the accuracy and quality of pharmaceuticals.
Laboratory Balances: ESP Series sensors are integrated into laboratory balances and precision scales used in scientific research, chemical analysis, and pharmaceutical laboratories, contributing to the accuracy of measurements.
Material Testing: In materials testing and quality control processes, ESP Series sensors are used in equipment like compression testers and tension testers to measure and record the force applied to materials during testing.
Customized Scales and Weighing Systems: OEMs integrate ESP Series sensors into customized weighing systems and scales designed for specialized applications, including industrial automation and material handling.
Quality Control: Industries across sectors use ESP Series sensors for quality control processes, ensuring products meet weight and force specifications before being distributed to customers.
Force Measurement in Production: ESP Series sensors are integrated into production processes to monitor and control forces in manufacturing and assembly operations, helping maintain product quality and consistency.
Load Monitoring: ESP Series sensors are used in load monitoring systems, such as load cells in conveyor systems and elevators, to ensure safe and efficient operation while preventing overloads.
The Transducer Techniques ESP Series single-point bending beam force sensor's combination of affordability, accuracy, and resistance to eccentric loading makes it an excellent choice for OEMs and various industries requiring precise force and weight measurements. These sensors contribute to improved product quality, efficiency, and cost-effectiveness across a broad range of applications.
SPL Series Force sensor Applications.
The Transducer Techniques SPL Series single-point force sensors are versatile and cost-effective solutions used in various industrial weighing applications and machinery. These sensors simplify scale designs, packaging machinery, and other equipment requiring precise force measurement. Here are some specific applications where the SPL Series single-point force sensor is commonly used:
Industrial Scales: SPL Series sensors are frequently integrated into industrial scales, including bench scales, platform scales, and floor scales, simplifying their design and reducing manufacturing costs. These scales are used in industries such as logistics, manufacturing, and agriculture for weighing materials, products, and components.
Packaging Machinery: Packaging machines, such as fillers, checkweighers, and bagging machines, incorporate SPL Series sensors to ensure accurate and consistent product packaging by measuring the weight of contents and containers.
Retail and Commercial Scales: Retailers and businesses use SPL Series sensors in commercial weighing equipment, including point-of-sale (POS) scales, deli scales, and postal scales, to facilitate precise weight measurements for pricing and inventory management.
Conveyor Systems: SPL Series sensors are integrated into conveyor systems for in-motion weighing and sorting applications in industries like logistics, e-commerce, and material handling.
Food Processing: The food industry employs SPL Series sensors in food processing equipment, such as portioning machines, to maintain product consistency and meet weight specifications.
Automated Packaging Lines: Manufacturers use SPL Series sensors in automated packaging lines to ensure that products are correctly weighed and packaged for distribution.
Pharmaceutical Manufacturing: Pharmaceutical companies utilize SPL Series sensors in pharmaceutical manufacturing equipment to monitor and control the weight of ingredients and ensure product quality and accuracy.
Quality Control: Industries across sectors use SPL Series sensors for quality control processes to verify that products meet weight and force specifications before they are shipped to customers.
Custom Machinery: OEMs and equipment manufacturers integrate SPL Series sensors into custom-designed machinery and systems for force measurement applications, simplifying design and reducing costs.
Damp Environments: SPL Series sensors' moisture-proof sealant makes them suitable for use in damp environments, such as washdown areas in food processing plants and outdoor weighing applications.
Multi-Point Weighing Systems: In applications where multiple load points need to be measured, the SPL Series simplifies the design by eliminating the need for multiple force sensors and summing boxes.
The Transducer Techniques SPL Series single-point force sensor's aluminum construction, moisture-proof sealant, and ability to simplify design make it a valuable choice in various industries requiring accurate and cost-effective force measurement solutions. These sensors contribute to improved product quality, efficiency, and cost-effectiveness across a wide range of applications.
SBL Series Force sensor Applications.
The Transducer Techniques SBL Series heavy-duty shear beam force sensors are designed for various industrial applications that require process weighing and low-profile scales. These economical and durable load cells are known for their ease of installation and reliability in the field. Here are some specific applications where the SBL Series shear beam force sensor is commonly used:
Industrial Scales: SBL Series sensors are widely integrated into low-profile industrial scales used for weighing materials, products, and components in manufacturing, logistics, and warehousing environments.
Platform Scales: These sensors are employed in platform scales used for weighing large and heavy items, such as pallets, drums, and containers. Platform scales are commonly used in shipping and warehousing.
Conveyor Belt Scales: In conveyor systems, SBL Series sensors are used in conveyor belt scales to measure the weight of materials as they move along the conveyor, ensuring accurate inventory management and process control.
Tank and Hopper Weighing: Industries utilize SBL Series sensors in tank and hopper weighing systems to monitor the weight of bulk materials, liquids, and powders in storage vessels.
Silos and Bins: Silo and bin weighing applications benefit from SBL Series sensors to ensure precise inventory control and prevent overfilling or underfilling of storage containers.
Batching and Mixing Systems: In industries like food processing, chemical manufacturing, and construction, these sensors are used in batching and mixing systems to accurately measure and control the addition of ingredients.
Automated Filling Machines: Manufacturers of automated filling machines integrate SBL Series sensors to measure and control the quantity of product dispensed into containers, ensuring consistent filling.
Material Handling Equipment: SBL Series sensors are employed in material handling equipment, including forklifts, conveyors, and elevators, to measure loads for safe and efficient transportation and handling.
Process Weighing: Industries engaged in process weighing, such as petrochemical, pharmaceutical, and food processing, use SBL Series sensors to monitor material flow and control production processes.
Low-Profile Scales: Low-profile industrial scales designed for applications where vertical space is limited and a low profile is required benefit from the compact design of SBL Series sensors.
Load Monitoring: SBL Series sensors are used in load monitoring systems, ensuring that equipment and structures operate within safe weight limits.
Heavy-Duty Applications: These sensors are designed for heavy-duty environments, making them suitable for harsh industrial applications that require durable and reliable force measurement.
The Transducer Techniques SBL Series shear beam force sensor's robust construction, environmental protection, and ease of installation make it a preferred choice in various industries for ensuring accurate and dependable weight measurement and process control. These sensors contribute to improved operational efficiency and quality assurance.
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