Jinzhou City Tujin Building Materials Co.,Ltd. , https://www.hpmctujin.com
1. Check the size of the mounting hole: If the size of the mounting hole is not appropriate, the threaded portion of the sensor is susceptible to wear during installation. This will not only affect the sealing performance of the equipment, but also make the pressure sensor unable to fully play its role, and may even cause potential safety hazards. Only suitable mounting holes can avoid thread wear (thread industry standard 1/2-20 UNF2B). Mounting holes can often be used to test the mounting holes to make appropriate adjustments.
2. Keep the mounting holes clean: Keeping the mounting holes clean and preventing clogging of the melt is important to ensure proper operation of the equipment. Before the extruder is cleaned, all pressure sensors should be removed from the barrel to avoid damage. When the sensor is removed, the molten material may flow into the mounting hole and harden. If these residual melts are not removed, the top of the sensor may be damaged when the sensor is installed again. The cleaning kit can remove these frit residues. However, the repeated cleaning process may deepen the damage caused by the mounting hole to the sensor. If this happens, steps should be taken to increase the position of the sensor in the mounting hole.
3, choose the right position: When the pressure sensor is installed too close to the production line, the unmelted material may wear out the top of the sensor; if the sensor is installed in the position too far, may be between the sensor and the screw stroke A stagnant zone of molten material can occur, where the molten material may degrade and the pressure signal may transmit distortion; if the sensor is too deep into the barrel, the screw may touch the top of the sensor during rotation and cause damage. In general, the sensor can be located on the barrel in front of the screen, in front of the melt pump, or in the mold.
4. The pressure transmitter is carefully cleaned; all sensors should be removed before using the wire brush or special compound to clean the barrel of the extruder. Because both of these cleaning methods may cause damage to the sensor's diaphragm. When the barrel is heated, the sensor should also be disassembled and wiped on top using a soft cloth that will not wear, and the sensor hole needs to be cleaned with a clean drill and guide bush.
5. Keep dry: Although the sensor's circuit design can withstand the harsh extrusion processing environment, most of the sensors can not be absolutely waterproof, nor conducive to normal operation in a humid environment. Therefore, it is necessary to ensure that the water in the water cooling device of the barrel of the extruder does not leak, otherwise the sensor will be adversely affected. If the sensor has to be exposed to water or a humid environment, special sensors with extremely high water resistance must be selected.
(1) In order to ensure the pressure measurement accuracy, the minimum pressure measurement value should be higher than 1/3 of the pressure gauge measurement range;
(2) Pressure sensors or pressure transmitters should be selected for applications requiring long distance measurement or high measurement accuracy;
(3) When the measurement accuracy is not high, a resistive or inductive Hall effect type remote pressure transmitter can be selected;
(4) The pneumatic base type pressure indicating regulator is suitable for local pressure indication adjustment;
(5) The pressure transmitter and pressure switch should be reasonably selected according to the explosion-proof requirements of the installation site.
Pressure Transmitters
Daily maintenance of pressure transmitter
Pressure transmitters are the most commonly used sensors in industrial practice. I will talk about the daily maintenance of pressure transmitters.