Pressure to current (P/I) converters are two-wire precision instrument designed to convert standard pneumatic input signals into proportional output electrical signal. They are compact robust instruments suitable for panel or field mounting applications.In this session we are going to discuss the calibration of P/I converter.
Input signal: 3-15 psig.
Output signal: 4-20 mA
DC Supply voltage: 24 VDC
Equipment needed calibration of P/I converter.
Supply voltage 24vdc,pressure source(handheld test pump), multimeter,
Calibration procedure calibration of P/I converter.
Generally P/I converter is calibrated for standard industrial signals as 3-15 psig input corresponds to 4-20 mA DC output. These are standard factory settings and need not to be changed. To adjust the zero and span settings proceed as follows: Two adjustments for zero and span are provided in front face of unit.
- Set digital calibrator on measure mode.
- Connect input signal i.e. 3-15 psig.
- Set the input signal to 3 psig and check the output current as 4 mA.
- If the current is showing more or less than 4 mA then adjust zero pot to make output 4ma.
- Set the input pressure signal to 15 psig and check the output current 20 mA.
- Turn the span adjustment potentiometer on Converter and adjust 100%.
- Repeat step 3 to check that the desired low value (3 psig ~ 4mA) has not changed after adjusting the span.
If necessary repeat steps 3 through 4 to fine-tune the unit.