How to measure cryogenic medium by electromagnetic flow meter transmitter
The measurement of low-temperature medium is that the transmitter is limited by two convenient, one is the low-temperature performance of the material, the second is the electrical insulation of the transmitter.
For general-more than 20 degrees of media, such as frozen brine, usually the transmitter lining materials can be used. But the use of PTFE material is, PTFE thermal expansion and contraction is more serious. Easy to make electrodes leak. The main problem in measuring cryogenic media is the electrical insulation of the transmitter. When the measurement tube is filled with a flowing low temperature medium, it is easy to take place in the measurement of the outer wall of the tube and the condensation water droplets or condensation frost in the transmitter. In this way, the insulation resistance between the signal circuit, the excitation circuit and the casing is reduced, even short circuit.
In this case, we can seal the shell with a resin or sealant. The use of transducer shell filled transformer oil to ensure that the insulation can also be directly filled with a resin transmitter shell inside the cavity, so that the electrical part of the air isolation.
For general-more than 20 degrees of media, such as frozen brine, usually the transmitter lining materials can be used. But the use of PTFE material is, PTFE thermal expansion and contraction is more serious. Easy to make electrodes leak. The main problem in measuring cryogenic media is the electrical insulation of the transmitter. When the measurement tube is filled with a flowing low temperature medium, it is easy to take place in the measurement of the outer wall of the tube and the condensation water droplets or condensation frost in the transmitter. In this way, the insulation resistance between the signal circuit, the excitation circuit and the casing is reduced, even short circuit.
In this case, we can seal the shell with a resin or sealant. The use of transducer shell filled transformer oil to ensure that the insulation can also be directly filled with a resin transmitter shell inside the cavity, so that the electrical part of the air isolation.
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