This slab-mounted snow sensor reliably detects snow and ice on concrete or asphalt when used in conjunction with the SCE-120 Economy Snow Melt Control. In particular, it detects moisture when the temperature is below 38°F. The sensor mounts in close proximity to the snow-melting cable to ensure the pavement and sensor become dry at similar time intervals. Maximum distance between the sensor and the control is 650 feet using 18 AWG wire. Note: Sensor wire must remain separate from any high-voltage wire to avoid a distorted sensor signal.