ACI High Temperature (HT) and Low Temperature (LT) sensors are air encapsulated. This allows the sensor to have a more stable output since the sensing element isn't subjected to the constant expansion and contraction of the encapsulation materials. The sensors are mounted in a 1/4" diameter stainless steel probe and have with either nickel plated fiberglass (HT) or teflon (LT) lead wires. Key components are rated up to 743 F for High Temperature Sensors and down to ‑328 F for Low Temperature Sensors.