Why does a 4–20 mA signal start from 4 mA instead of 0 mA? This concept is known as Live Zero and is one of the most important fundamentals in Instrumentation & Process Control. 4 mA represents 0% of the process value, while 20 mA represents 100%. Using 4 mA as the minimum signal helps detect wiring faults, transmitter failures, and open circuits more easily, making industrial measurements more reliable. Save this infographic for future reference and share it with fellow engineers, technicians, and students. Post navigation Understanding the Difference Between Ladder Diagrams, Wiring Diagrams, and Pictorial Diagrams DIFFERENTIAL PRESSURE (DP) MEASUREMENT
