A quick three-step process can be used: "Offline initial screening → Online verification → Comparative validation," with results available in 10 minutes:
1. Step One: Offline Initial Screening (No need to power on the device; first rule out dimensional tolerance issues)
First, verify the core dimensions of the replacement sensor:
Check the exposed length of the probe: Compare with the original sensor; a deviation exceeding 0.2mm easily increases heat conduction error, likely exceeding the tolerance;
Installation thread tolerance: Use a go/no-go gauge to measure the thread, or directly screw it into the mounting hole; a wobble exceeding 0.1mm indicates a large dimensional tolerance, and interchangeability error is likely to exceed the standard.
2. Second Step: Online Temperature Stabilization Testing
After the hot runner reaches the set temperature (generally 180-300℃), hold for 15 minutes to allow the temperature to stabilize completely:
Temperature Sensor: Use a calibrated handheld infrared thermometer (accuracy within ±0.5℃) to directly measure the nozzle surface. Compare the sensor readings with the control system display: a deviation > ±2℃ indicates an excessive error.
Pressure Sensor: After no-load injection molding, compare the zero-pressure output. A difference between the output of the replacement sensor and the original sensor > ±2%FS indicates an excessive error.
3. Third Step: Cross-Verification and Confirmation
Reinstall the old sensor and re-stabilize the temperature, observing the readings:
If the deviation decreases to within 1℃ after replacing the old sensor, the problem is indeed an interchangeability error of the replacement part, not a temperature control issue with the hot runner itself.
If the deviation exceeds the range, it will directly lead to inaccurate temperature/pressure control during injection molding, easily resulting in material shortages, flash, or fluctuations in finished product dimensions. It is recommended to replace the sensor with one that meets the accuracy requirements.
