Pressure sensor installation precautions - Solutions - Huaqiang Electronic Network

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First, the correct installation of the normal high temperature melt pressure sensor damage is caused by improper installation position, if the sensor is forcibly installed in too small holes or irregularly shaped holes, it may cause the sensor's diaphragm Damaged by impact, choose the right tool to process the mounting hole, which is beneficial to control the size of the mounting hole. In addition, the proper mounting torque is good for forming a good seal, but if the installation torque is too high, it will easily cause the high temperature melt pressure sensor to slip off. To prevent this from happening, it is common to apply a release compound to the threaded portion of the sensor prior to installation.


Second, check the size of the mounting hole If the size of the mounting hole is not suitable, the high-temperature melt pressure sensor during the installation process, the threaded part is very susceptible to wear, which will not only affect the sealing performance of the device, but also make the sensor not fully function It may even pose a security risk. Only the proper mounting holes can avoid thread wear (Thread Industry Standard 1/2-20UNF2B). Mounting holes can usually be tested with a mounting hole gauge to make the appropriate adjustments.

3. Keep the mounting holes clean. Keeping the mounting holes clean and preventing the clogging of the melt is very important to ensure the normal operation of the equipment. All high temperature melt pressure sensors should be removed from the barrel before the extruder is cleaned. To avoid damage. When the sensor is removed, the melt may flow into the mounting hole and harden. If the residual melt is not removed, the top of the melt may be damaged when the high temperature melt pressure sensor is installed again. The cleaning kit can The melt residue is removed, however, repeated cleaning processes may deepen the damage to the high temperature melt pressure sensor caused by the mounting holes. If this happens, measures should be taken to raise the position of the high temperature melt pressure sensor in the mounting hole.

4. Choosing the right position When the high temperature melt pressure sensor is installed too close to the upstream of the production line, the unmelted material may wear the top of the sensor; if the high temperature melt pressure sensor is installed in the too late position, at high temperature There may be a stagnant zone of molten material between the melt pressure sensor and the screw stroke. The melt may be degraded there, and the pressure signal may also transmit distortion. If the high temperature melt pressure sensor is too deep into the barrel, the screw may rotate. The top of the high temperature melt pressure sensor is touched during the process and is damaged.
5. Careful cleaning All high-temperature melt pressure sensors should be removed before cleaning the extruder barrel with wire brushes or special compounds, as both cleaning methods may cause high-temperature melt pressure sensors. The diaphragm is damaged. When the barrel is heated, the high temperature melt pressure sensor should also be removed and wiped with a soft cloth that does not wear out. The hole in the high temperature melt pressure sensor also requires a clean drill and guide sleeve. Clean up.
6. Keep dry Although the sensor's circuit design can withstand the harsh extrusion processing environment, most sensors are not absolutely waterproof, and it is not suitable for normal operation in humid environments. Therefore, it is necessary to ensure that the water in the water cooling device of the extruder barrel does not leak, otherwise the sensor will be adversely affected. If the sensor has to be exposed to water or moisture, choose a special sensor that is extremely water resistant.
VII. Avoiding low-temperature interference In the extrusion production process, for plastic raw materials, there should be sufficient “soaking time” from solid to molten state. If the extruder does not reach the operating temperature before starting production, both the sensor and the extruder will be damaged to some extent. In addition, if the sensor is removed from the cold extruder, the material may stick to the top of the sensor causing damage to the diaphragm. Therefore, before removing the sensor, make sure that the temperature of the barrel is high enough and the material inside the barrel is softened.
8. Preventing pressure overload Even if the overload design of the sensor's pressure measuring range can reach 50% (out of the maximum range ratio), it should be avoided as far as possible from the safety point of view of equipment operation. It is best to choose the measured pressure within the range of the range. Sensor. Under normal circumstances, the optimal range of the selected sensor should be twice the measured pressure, so that the sensor can be damaged even if the extruder is operated under extremely high pressure.