Off-axis loading refers to a situation where a load cell, which is a device designed to measure force or weight, is subject to forces that are not aligned with its primary sensing axis. Load cells are typically designed to measure forces that are applied along a specific direction or axis, which is known as the primary sensing axis. When forces are applied to the load cell in other directions, this is referred to as off-axis loading.
Off-axis loading can affect the accuracy of load cell measurements, as the load cell may not be able to accurately distinguish between forces that are applied along the primary sensing axis and forces that are applied in other directions. This can result in errors in the measured weight or force.
To minimize the effects of off-axis loading, load cells are often designed with measures to reduce sensitivity to forces applied in other directions. These may include mechanical features such as strain relief structures or specialized materials that are more resistant to off-axis loading. Additionally, load cells are often installed and used in ways that minimize the likelihood of off-axis loading, such as aligning the primary sensing axis with the direction of the applied force. Be sure to carefully follow all Force Measurement Installation Guides provided with sensor.
What can be done to protect from off-axis loading?
Off-axis loading can affect the accuracy of load cell measurements, so it is important to take steps to protect against it. Here are a few ways to do so:
- Use proper mounting and alignment: Load cells should be mounted and aligned in a way that ensures that the primary sensing axis is aligned with the direction of the applied force. This helps to minimize off-axis loading and ensure accurate measurements.
- Use appropriate accessories: Using accessories such as adapters or mounting bases can help to ensure that load cells are properly aligned and oriented, minimizing the potential for off-axis loading.
- Use anti-rotation features: Many load cells are equipped with anti-rotation features, such as bolt-hole patterns or keyway slots, which help to prevent the load cell from rotating around its mounting point. This can help to maintain proper alignment and reduce the effects of off-axis loading.
- Use overload protection: Overload protection features, such as limit switches or stoppers, can be used to prevent load cells from being subjected to excessive forces or moments. This can help to prevent damage to the load cell and ensure accurate measurements.
- Use a protective enclosure: Load cells can be placed in protective enclosures that shield them from external forces and environmental factors. These enclosures can help to protect against off-axis loading, as well as other types of interference.
By taking these steps, load cell users can help to protect against the effects of off-axis loading and ensure accurate and reliable measurements.
Product designs that mitigate off-axis loading
Engineers are constantly working to design new load cells that are more resistant to off-axis loading. In fact, Interface product engineers have several products that are designed to protect from off-axis loading, including:
- ConvexBT Load Button Load Cell
- SuperSC S-Type Miniature Load Cell
- MBP Overload Protected Miniature Beam Load Cell
- MRTP Miniature Overload Protected Flange Style Reaction Torque Transducer
- MBI Overload Protected Miniature Beam Load Cell
- LBMP Overload Protected Compression Load Button Load Cell
- SMT Overload Protected S-Type Load Cell
- WMCP Overload Protected Stainless Steel Miniature Load Cell with Male Threads
By optimizing the mechanical design of load cells to minimize their sensitivity to off-axis loading this can include use of materials, such as composites or alloys, which are more resistant to deformation and strain. It also includes the use of specialized geometries that can help to distribute forces more evenly and reduce the effects of off-axis loading.
As well, engineers utilize built-in electronic compensation to correct for the effects of off-axis loading. This may involve using additional sensors or feedback loops to monitor the load cell’s response to external forces and adjust the output accordingly.
Interface engineers use a multi-disciplinary approach to designing load cells that are more resistant to off-axis loading. By combining advances in mechanical design, electronics, manufacturing, and simulation, they are creating load cells that are the most accurate in by classification in the world.