Pt 100 1 platinum resistance signal is usually connected to display control instrument, DCS or PLC by three-wire connection. If one wire is removed, the measuring loop becomes two-wire system or disconnected. This kind of display control instrument, DCS or PLC, is used as a single-line sensor to detect, and the display value is the largest, so it will naturally report to the full range. Welcome to the "Technical Library" column of Changhui Instrument Network to learn more about automation.