4-20 mA Temperature Transmitters

Temperature transmitters are important components for nearly any process control application that requires temperature monitoring. These transmitters receive a signal from a thermocouple or RTD, convert that signal to one stronger and more stable, scale the new signal according to a preset range, and send the new signal to other instruments—such as a panel meters, controllers, or recorders—which will use the signal to either activate another part of the process or to display or record measurements.

Temperature and other transmitters often use 4-20mA signals. Analog current loops, such as 4-20mA, offer simplicity as well as increased immunity to both electrical interference and signal loss over long cable runs. The loop can also facilitate communications via the HART protocol and provide a power source for some 4-20mA field devices, eliminating the need for a separate power source. These benefits have made current loops—particularly 4-20mA current loops—the de facto industry standard for electrical signals in process control applications.