Pressure transmitter calibration standards1

1, preparation work

pressure source through a rubber tube connected to the homemade joint, close the balance valve, and check the seal gas path, then the ammeter ( Voltmeter) , hand device connected to the transmitter output circuit, after electrify preheating start calibration. We know that no matter what type of differential pressure transmitter, its positive and negative pressure chamber has a vent, drain valve or cock; It's for our field calibration differential pressure transmitter provides a convenient, that is to say, don't dismantle guide tube can be calibrated differential pressure transmitter. Calibration for differential pressure transmitter, the first three valve group, the positive and negative valve closed, open the balance valve, then unscrew bleed, drain valve or cocks vent, and then with homemade sub instead of positive pressure chamber exhaust, drainage valve or cock; The negative pressure chamber is keep unscrew, make it through the atmosphere.

2, calibration of conventional differential pressure transmitter

damping adjustable to zero state, first to the zero point, and then filled with pressure adjustable full scale, make the output to 20 ma, calibration on site is fast, the zero point, fast calibration method of range. Tone has no effect on full almost zero, but the full, influential to zero when without migration its influence is about 1/5 the amount of range adjustment, namely range adjusted upward 1 ma, zero point will move up about 02 ma, and vice versa.

3, the calibration of intelligent differential pressure transmitter

with the conventional method for calibration of intelligent transducer is no good, because this is determined by the HART transmitter structure theory. Because smart transducer in the input pressure source and produce 4 - Between 20 ma current signal, in addition to the machinery, circuit, and microprocessor chip operation work of the input data. So calibration with conventional method.