Calibration method for differential pressure flow transmitter

Calibration method for differential pressure flow transmitter

As a kind of testing instrument, the differential pressure flow transmitter is the most important in the process of using it. It is verified under the premise of mastering the correct operation method. How to check it? Let's take a look at it.

Before the pressure flow transmitter is adjusted, the damping potentiometer W4 should be turned counterclockwise to the end to make the damping close.
Before the zero-point and span calibration of the differential pressure flow transmitter, the migration should be canceled (ie, the migration plug on the amplifier board is inserted into the middle position without migration, the migration resistance is disconnected), and then the zero point and span adjustment are performed. .
The technical conditions of the differential pressure flow transmitter stipulate that the positive migration amount can reach 500%, and the negative migration amount can reach 600%. However, the measured pressure after migration shall not exceed the absolute value of the upper limit of the measurement range allowed by the meter, nor shall the range be compressed to the minimum range allowed by the meter.

The power signal terminal of the differential pressure flow transmitter is located on the wiring side inside the electrical housing. When wiring, the cover with the “wiring side” on the nameplate can be opened. The upper terminal is the power signal terminal and the lower terminal is the test or indicator terminal. .
Be careful not to connect the power signal line to the test terminal, otherwise the internal diode will be burned out. In the event of burnout, the two test terminals can be shorted for proper operation of the transmitter.
Differential pressure flow transmitter adopts differential capacitance as the whole structure without detecting mechanical transmission and adjustment device. All adjustments are realized by adjustment of electrical components. It is essentially a converter that linearly converts the input differential pressure signal Δрi into a standard 4-20 mA DC current signal output.
The verification method of the differential pressure flow transmitter is simple to introduce to you, and everyone can have problems in the verification process.

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