How to debug when the differential pressure transmitter has no output

How to debug when the differential pressure transmitter has no output

We all know that the application of differential pressure transmitters is very extensive. In general, it is used to prevent the medium in the pipeline from directly entering the transmitter. The pressure-sensitive diaphragm and the transmitter are connected by a capillary filled with fluid. stand up. It is used to measure the level, flow and pressure of liquid, gas or steam, and then convert it into 4 ~ 20mADC signal output. However, even when there are errors in the product, the main content of this article is about how to debug when the differential pressure transmitter has no output. Why take this fault as an example, because the situation of no output of the transmitter is very common, it does not mean that the quality is low, but because of the following reasons.

1. Check whether the power supply of the differential pressure transmitter is reversed, and whether the positive and negative power supply is connected correctly.

2. When measuring the power supply of the transmitter, whether there is a 24V DC voltage must ensure that the power supply voltage supplied to the transmitter is 212V (that is, the voltage at the input terminal of the transmitter power supply is greater than or equal to 12V). If there is no power supply, check whether the circuit is broken, whether the detection instrument is selected incorrectly (input impedance should be ≤250Q), etc.

3. If the pressure transmitter has a meter head, it is necessary to check whether the meter head is damaged (you can short-circuit the two lines of the meter head first, if it is normal after the short circuit, it means that the meter head is damaged), if the meter head is damaged, The header needs to be replaced.

4. If there is a problem with the differential pressure transmitter, you can connect the ammeter in series with the 24V power circuit to check whether the current is normal. If it is normal, it means that the transmitter is normal. At this time, you should check whether other instruments in the loop are normal.

5. Whether the power supply is connected to the power input end of the transmitter, and connect the power cord to the power connection port.