Introduction to the correct wiring method for high temperature pressure transmitter

Today, Xiaobian brings you the wiring method of high temperature pressure transmitter. If you don't say much, please follow along with Xiaobian.

1. When the high temperature pressure transmitter has no reference terminal temperature automatic compensation, the transmitter verification wiring

(1) Used when the high temperature pressure transmitter is not automatically compensated by the reference end temperature.

(2) When the thermocouple high-temperature pressure transmitter with compensation is proofed by the practical measurement method, this wiring method is also adopted:

Place a thermometer at the input end of the transmitter, measure the temperature value of the cold junction, find the temperature potential value Eω by the index table, and output it by the millivolt signal generator according to the potential value E0 of the thermocouple index table (E0 The value of -Eω), that is, the output of the analog thermocouple, measures the current output value of the thermocouple high temperature pressure transmitter 4-20 mA, and calculates the measurement accuracy of the transmitter. This method has two aspects: ambient temperature change and thermometer measurement cold end error, which cannot eliminate the measurement error caused by these two aspects. Therefore, it is usually used as a zero-time comparison measurement in the field, and is not used as a verification check for high-temperature pressure transmitters.

2, high temperature pressure transmitter with reference terminal temperature automatic compensation wiring

(1) When the input signal is a thermocouple, verify that the intelligent high temperature pressure transmitter is wired according to this figure. The wiring of high temperature pressure transmitters produced by other manufacturers is also the same.

(2) The thermocouple compensation wire adopts the compensation wire corresponding to the measurement thermocouple; the mV signal generator is used to simulate the thermocouple signal; the ice-tube container is in the mixed state of ice and water, and the temperature of the cold end is kept at 0 °C.

(3) Precision measurement method for high temperature pressure transmitter:

According to the corresponding potential value on the thermocouple index table, the thermocouple output signal is directly simulated by the millivolt signal generator, and the 4-20 mA signal output by the high temperature pressure transmitter is measured to calculate the measurement accuracy of the transmitter.

This measurement method can eliminate the measurement error caused by the cold junction temperature change during the measurement process, but the measurement error caused by the compensation line itself cannot be eliminated. This method is typically used during laboratory measurements and factory calibration of high temperature pressure transmitter manufacturers.