W Why we don’t use 2-20mA, 1-20mA, 3-20mA or 10-50mA signal instead of 4-20mA ? August 5, 2021 1 Min Read 0 2 August 5, 2021 1 Min Read 0 2 Answer : Generally, in a transistor some amount of voltage is required for turning it on… Instrumentation Editor Continue Reading