TTSIM-1A Sensor Interface Module monitors up to 150 meters (500 feet) of TraceTek sensing cable. When liquid is detected, the TTSIM-1A unit indicates the leak with an LED, and switches a relay to provide local voltage-free contact closure. The TTSIM-1A can also communicate to a host monitoring system such as a TraceTek TTDM-128 or directly to a PLC or other host system using standard protocols. The low cost of the TTSIM-1A makes it economical to build very robust systems with many small independent sensing cable segments. No field calibration is required.