Shear beams are a type of load cell that use the principle of shear stress to measure force. They convert a mechanical force into an electrical signal which is then calibrated to give precise weight readings. Understanding how they work is the first step to getting the most out of this device whether in a lab, factory or heavy duty industrial environment.
Let’s take a look at how they are designed, what they do and where they excel.
A Brief History of Shear Beam Load Cells
Load cells have evolved from simple mechanical balances to electronic sensors. Early industrial weighing used bending beams and spring mechanisms which were prone to inaccuracies under uneven loads. As industrial demands grew, shear beam load cells were developed to give higher capacities, better off-center load resistance and improved precision making them the standard in heavy duty industrial applications.
This explains why shear beams are now trusted in industries like mining, oil and gas, agriculture and manufacturing.
A Closer Look at the Design and Function of Shear Beam Load Cells
At its core, a shear beam load cell is a specialized sensor that measures force or weight by exploiting the principle of shear stress. Unlike other types of load cells such as bending beam load cells which measure bending strain, shear beam load cells work by concentrating strain in a specially machined section of the metal beam.
This section often shaped like an “I-beam” or web, allows the majority of the shear strain to be focused in one area. Strain gauges are bonded to this critical region and deform along with the metal when a load is applied and the cell can detect even the smallest change in force.
Shear beam is used for higher capacities and is very accurate, bending beam load cells are used for lower capacities and are less accurate. Because of their rugged construction and ability to withstand harsh environments these load cells are trusted by industries where precision and reliability are non-negotiable.
How Does a Shear Beam Load Cell Work?
When a load is applied the metal beam deforms slightly and the strain gauges attached to the shear web stretch or compress accordingly. This deformation changes their electrical resistance and creates a signal that reflects the applied force. To get the most accuracy and reliability shear beam load cells often use a Wheatstone bridge configuration. This uses four strain gauges in a diamond pattern: two gauges increase in resistance under tension and two decrease under compression. This imbalance creates a differential voltage which is then amplified and sent to an indicator or controller and converts the electrical signal into a readable weight measurement.
Because shear beams measure force not weight directly calibration is required to translate this force into weight readings. Their design also minimizes errors from off-center loads, lateral forces or temperature variations making them very reliable in industrial applications.
What Are Shear Beam Load Cells Used For?
Shear beam load cells are versatile in industrial and laboratory environments. Applications include:
- Weighing raw materials and shipments for quality control.
- Inventory monitoring and production dosing.
- Safety monitoring, where overload conditions can be detected to prevent equipment damage or accidents.
Industries that benefit the most include mining, oil and gas, agriculture and manufacturing, essentially any environment where forces are high and conditions are challenging.
How Accurate Is a Shear Beam Load Cell?
In ideal conditions and properly calibrated shear beam load cells can achieve accuracies up to 0.02% FS or better, especially when NTEP Class III certified. Their rugged design helps maintain precision even under uneven loading or environmental stress.
Shear Beam vs Bending Beam Load Cells
| Feature | Shear Beam Load Cell | Bending Beam Load Cell |
| Measurement Principle | Shear strain | Bending strain |
| Capacity Range | Medium to high (500 kg – 10 tons) | Low (<500 kg) |
| Accuracy | High precision, resistant to off-center loads | Moderate, sensitive to side loads |
| Robustness | Withstands harsh environments, lateral/torsional forces | Less robust, less suitable for harsh conditions |
| Common Applications | Truck scales, tank weighing, platform scales | Small scales, low-capacity laboratory weighing |
This comparison shows why shear beams are used in demanding industrial environments and bending beams are used for smaller simpler applications.
Technical Specifications and Environmental Considerations
Shear beam load cells are built for durability and high performance:
- IP Ratings: Many shear beam load cells are dust and moisture proof (IP66/IP67 typical).
- Temperature Range: Designed to operate across extreme temperatures found in industrial environments.
- Capacity Range: Standard capacities from a few kg to several tons; custom options available for special applications.
These specifications make shear beams suitable for many industrial applications and long term reliability.
Common Myths About Shear Beam Load Cells
- “Load cells measure weight.”: Shear beam load cells measure force which is then calibrated to give weight readings.
- “Shear beams and bending beams are interchangeable.”: Shear beams are for medium to high capacity and side load tolerance, bending beams are not suitable for demanding conditions.
- “Off-center loads don’t affect accuracy.”: While shear beams are more resistant than bending beams, extreme off centre loading can still affect readings if installation guidelines are not followed.
Clearing up these myths will help you make a better decision when choosing and using load cells.
What Makes Shear Beam Load Cells Unique?
Shear beam load cells are:
- Rugged: Machined from durable metals like steel or aluminum to withstand harsh conditions.
- Precise: Exceptional accuracy due to focused shear strain and Wheatstone bridge circuitry.
- Versatile: For static weighing, dynamic force measurement and process monitoring.
- Easy to Install: Designed for quick and hassle free integration.
- Low Maintenance: Minimal upkeep to maximise uptime.
- Environmental Resilience: Withstand extreme temperatures, moisture, vibration and side loads.
- Cost Effective: Advanced technology with long term value.
Shear beam load cells are often preferred over bending beam load cells for medium to high capacity applications where side loads, off centre loading or industrial wear are a concern.
Shear Beam Load Cells as OEM Solutions
Shear beam load cells can be integrated into OEM equipment for:
- Weight Measurement: Accurate load sensing for industrial machinery.
- Process Optimisation: Precise hopper or bulk mixing measurements.
- Quality Control: Product consistency in production lines.
- Safety Monitoring: Overload detection in lifting or hoisting equipment.
- Integration Flexibility: Compatible with many equipment designs and configurations.
Contact Massload for Double-Ended Shear Beam Load Cells
Massload’s standard range includes:
- 400 Double-Ended Shear Beam Load Cell;
- 500 Double-Ended Shear Beam Load Cell;
- 600 Low Profile Double-Ended Shear Beam Load Cell Transducer;
- 1200 Double-Ended Shear Beam Load Cell;
All are made with:
- Precision in Canada’s only VCAP (Verified Conformity Assessment Program) certified load cell manufacturing facility.
- NTEP certified for legal-for-trade weighbridge truck scales.
- 4340 Alloy Steel or 17-4PH Stainless Steel options.
- Designed for tank weighing, truck and railway scales.
- Custom options available.
Get in touch with our technical sales team to find the right load cell for your application.
