Sov

A solenoid valve changes state when it is energized and/or de-energized.

Fieldbus is a generic term for a digital device communication protocol and control architecture that also includes physical layer specifications. Profibus, Modbus, and Foundtion Fieldbus are specific examples.

With linear pressure transmitters there is a proportional relationship between the range of the pressure and the range of the output mA. For example when the pressure is at 50% the output should be 50%.

if one transmitter range is 0 to 25 bar,i get output 15 ma ,hw I calculate through pressure

0-25 bar = 4-20 mA

0 bar=4mA

25 bar=20mA

What does 15mA =?

If you set 25bar to 20mA,what will happen if pressure exceeds 25bar?. It would be advisable to allow a safety margin for small over-pressure. You can set 25bar at,say, 18mA.

No you should not set 18 mA for 25 bar it will lead to wrong measurement.

And if we consider the case where 25 bar is set to 20mA and pressure exceeds from 25 bar then transmitter will send fault current 22mA proportional to preesure and after that it will clamp to 22mA (if its not NAMUR compliant).

Sir, pressure transmitter will never come with square route . its always linear relation only if u dont know how to say dont confuse others..

take care

The solenoid converts electrical energy into mechanical energy which, in turn, opens or closes the valve mechanically. For working please refer http://www.pneumaticpart.com/solenoid-valve/Solenoid-operational-principle.html

Process Instrumentation and Control - Continuing Education