High Accuracy Considerations
Your strain gage measurements can be inaccurate due to one or more factors. The following table lists these errors and ways to minimize each type of error.
| Error Type | How to Minimize the Error |
|---|---|
| Gain | Perform frequent shunt calibration. Use a remote sensor to account for excitation voltage drop across lead wires. Use a strain gage with a higher precision gage factor. Accurately specify shunt resistance by manually measuring it. |
| Offset | Perform frequent offset nulling. Use precision completion resistors (for quarter-bridge and half-bridge setup). Check the gage resistance of your strain gage. Use a remote sensor to account for voltage drop across lead wires. Check the accuracy limitation of the offset nulling circuit. |
| Noise | Over-sample your data. Use a hardware lowpass filter. Use a software lowpass filter. |
| Temperature Drift | Perform frequent calibration. Use a temperature-compensated bridge type (all except quarter-bridge I). |