Differential pressure transmitter is a commonly used transmitter type, after long-term use, in order to ensure its better operation and accurate measurement, the differential pressure transmitter needs to be regularly checked and calibrated. Usually the differential pressure transmitter is connected by a catheter, so it is necessary to remove the joint between the pressure guide tube and the differential pressure transmitter, and then connect the pressure source to verify it. However, this situation has some drawbacks, not only labor intensity, but also in the process of disassembling the pressure pipe, it is easy to break or leak. Today I will explain to you another method to facilitate the on-site verification of differential pressure transmitters. For various types of differential pressure transmitters, the positive and negative pressure chambers have exhaust, drain valves or stopcocks, through which we can not disassemble the pressure pipe, so as to accurately verify the differential pressure transmitter. Before calibrating the differential pressure transmitter, it is necessary to close the positive and negative valves of the three-valve group, open the balance valve, and then loosen the exhaust, drain valve or stopcock, and replace the exhaust, drain valve or stopcock connected to the positive pressure chamber with a self-made joint; The negative pressure chamber, on the other hand, is kept loose to ventilate the atmosphere. The pressure source is connected to the self-made joint through the rubber tube, the balance valve is closed, and the air circuit seal is checked, and then the ammeter (voltmeter) and hand communicator are connected to the transmitter output circuit, and the preparation for calibration is started after the power is preheated. The specific calibration process of the differential pressure transmitter: first adjust the damping to the zero state, first adjust the zero point, and then fill the full pressure to adjust the full scale, so that the output is 20mA, and the on-site adjustment is fast. When adjusting the zero point, it has almost no effect on the full-scale, but when adjusting the full-scale, it has an effect on the zero point, and the effect is about 1/5 of the range adjustment without migration. After the zero point and full scale of the differential pressure transmitter are adjusted normally, check the intermediate scales to see if they are out of tolerance, and fine-tune them if necessary. Then the adjustment work of migration, linearity, and damping is carried out. For any questions such as product consultation, product customization, agent, technical inquiry, quotation, etc., please contact Star sensor hotline: 400-600-4496!
