To ensure the accuracy of the interchange verification method, the core is to control all irrelevant variables and only exchange the sensor positions. By paying attention to these 5 key details, the accuracy rate can reach 99%:
1. Strictly Maintain Consistent Installation Parameters
The tightening torque must be exactly the same as the original installation: Use a torque wrench to calibrate each sensor individually; do not tighten by feel, as torque differences will directly cause deformation deviations and interfere with the results.
The installation depth must be completely consistent: If it is a screw-in installation, ensure that the number of turns for both sensors is the same as before, ensuring that the relative position of the sensing surface and the flow channel remains unchanged.
2. Sufficient Thermal Stabilization Waiting Time
After installation, the temperature must be raised to the normal operating temperature and then kept at that temperature for at least 2 hours for stabilization:
Uneven temperature will cause different sensor expansion amounts, resulting in temporary deviations. Testing immediately after heating will yield incorrect results.
Use a temperature gun to confirm that the temperature difference between the two sensor housings is ≤1℃ before starting the test.
3. Test conditions must be completely consistent with the original test.
Use the same injection molding process: produce with the exact same product and pressure parameters as before the swap. Do not change the process/materials for testing.
Use the same test conditions: for zero-pressure tests, wait 10 minutes after mold opening before measuring. For full-scale tests, maintain the same holding pressure as before. Comparisons under inconsistent test conditions are meaningless.
4. Take the average of multiple measurements.
Measure at least 3 times for each condition (zero pressure/rated pressure), with 5-minute intervals between each measurement. Take the average deviation for comparison:
Avoid misjudgments caused by random fluctuations in a single measurement.
If the deviation fluctuation of 3 measurements exceeds 0.02%FS, it indicates that the temperature or pressure has not yet stabilized and further waiting is required.
5. Eliminate wiring/data acquisition channel interference.
If the two sensors use different data acquisition channels, the wiring can be swapped during the swap:
Connect sensor A to the original data acquisition channel of sensor B, and sensor B to the original channel of sensor A. This eliminates errors inherent in the data acquisition channels themselves.
If the deviation follows the channel after swapping the wiring, it indicates a problem with the data acquisition channel, not the sensor or installation.
If you do these things well, the results will be completely accurate, and you can 100% distinguish between installation problems and sensor problems, without any misjudgments.
