Control Valve · Glossary

What is an I/P Converter?

4 to 20 mA to 0.2 to 1 barControl Valve

An I/P converter changes a 4 to 20 mA current signal into a proportional pneumatic signal, usually 0.2 to 1.0 bar (3 to 15 psi).

I/P Converter Explained

I/P converters drive pneumatic actuators or pneumatic positioners from electronic controllers. Inside, a coil moves a flapper against a nozzle to set output pressure.

Most smart positioners include the I/P function, so separate converters are less common today.

I/P Converter Formula

P = 0.2 + 0.8 × (I − 4) ÷ 16 bar

I	input current (mA)
P	output pressure (bar g)

Example: 12 mA gives 0.6 bar g (9 psi).

Calculators for I/P Converter

CalculatorAnalog Scaling CalculatorFree online calculator with formula and worked example.CalculatorSplit Range CalculatorFree online calculator with formula and worked example.

Frequently Asked Questions

What is an I/P Converter?

An I/P converter changes a 4 to 20 mA current signal into a proportional pneumatic signal, usually 0.2 to 1.0 bar (3 to 15 psi).

Why does an I/P need clean air?

The nozzle is tiny; oil, water or dirt block it and shift the output.

Can an I/P stroke a large actuator alone?

It can, but slowly; a booster or positioner gives better speed and accuracy.

Learn more on the blog

Control valve positioner working

A practical guide on instrumentationblog.in with more detail on I/P converter and how it is applied on real plants.

Read Full Article

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