Based on the magnitude and cause of the deviation, the following solutions are provided, from easiest to most difficult. In most cases, direct sensor replacement is not necessary:
1. Small Deviations (Temperature ≤ 3℃/Pressure ≤ 3%FS): System Calibration Compensation (Solved in as little as 10 minutes)
This is the most commonly used low-cost repair solution, requiring no machine disassembly:
Temperature Sensor: Locate the temperature compensation parameter for the corresponding channel in the injection molding machine's temperature control system and adjust it according to the direction of the deviation. For example, if the sensor reading is 2℃ higher than the actual temperature, set the compensation value to -2℃. After correction, the deviation can be reduced to within ±1℃.
Pressure Sensor: In a no-load standby state with zero pressure, call the system's zero-point calibration function to recalibrate the zero point. This will eliminate most zero-point deviations caused by interchangeability.
2. Deviations Caused by Installation Dimension Tolerances: Adjust the Installation Structure
If the thermal conduction error is caused by a mismatch in probe length:
Probe Too Long: Use a lathe to micro-machine the probe end face to ensure that the probe and the bottom surface of the hot runner detection are completely fitted after installation, eliminating gap errors.
3. Probe Too Short: Place a piece of thermally conductive copper foil of matching thickness at the probe tail to fill the gap and ensure the probe tip is in close contact with the detection surface. This can reduce temperature deviation by 1-2℃.
4. Output Protocol Mismatch: Add a Signal Conversion Module. If the output range of a smaller brand sensor is incompatible with the original system, there's no need to replace the sensor. Simply add a compatible signal conversion module to adjust the output to the 0-10V/4-20mA standard signal supported by the original system to correct the deviation.
5. Large Deviation (Temperature > 3℃ / Pressure > 3%FS): Replace with a Compliant Product. If the above adjustments fail to improve the situation, it indicates that the sensor itself is not manufactured to the required precision. It is recommended to replace it with a mainstream brand sensor that conforms to general industry standards: prioritize products with dimensional tolerances ≤ 0.05mm and factory-calibrated individual products to resolve the interchangeability error problem at its source.
