Instrumentation Engineering Interview Question:

Why plc require in analog input 4-20amp & 0-10 volt?

Submitted by: Vishnuprasad

Because these are the signals which can change with respect to signal.4-20 mA signal is use because if it can start from 0-20 then if there is an signal of instrument is not equal to or less then original signal and if there instrument is show 10% open valve at 4 mA then we can test it with giving it less then 4 mA.
Submitted by: Rahul Khatri