Most load cell returns are specification errors rather than manufacturing defects. Working through a short checklist before ordering avoids nearly all of them.
The questions
1. What is the maximum working load, including shock? 2. Is the load tension, compression, or both? 3. How much space is available, and what mounting hardware exists? 4. What accuracy class does the application actually need? 5. What is the temperature range in service? 6. Is water, dust or washdown present? 7. Are there flammable atmospheres? 8. What output does the instrument accept? 9. How long is the cable run? 10. How many cycles per day? 11. Is there side load or bending moment? 12. What certification or calibration certificate is required?
Reading the answers together
The answers interact. A washdown food plant with high cycle counts needs stainless construction, IP69K, and a capacity margin for dynamic loads. A silo in a windy site needs self-aligning mounts and separate restraint. A trade application fixes the accuracy class by law, which in turn constrains the indicator and the calibration interval.
The one question people forget
How will the cell be replaced? A design that requires cutting a welded frame to change a cell will be maintained badly. Leave access, use connectors rather than hard wiring, and keep the calibration record with the machine.
Kevin Huang