The Dwyer HHT Hazardous Area Humidity/Temperature Transmitter provides accurate measurements in harsh environments. It is offered in explosion-proof (HHT-EX) and intrinsically safe (HHT-IX) versions to meet application requirements. The explosion-proof model provides 4–20 mA output for humidity only; the intrinsically safe version provides 4–20 mA for humidity and temperature. An optional two-line alphanumeric display shows current humidity and temperature.

Specifications: relative humidity range 0–100% RH, temperature range -40 to 60°C, accuracy ±2% RH (10–90% RH) and ±0.9°F at 72°F (±0.3°C at 25°C), repeatability ±0.1% typical. Outputs are 4–20 mA (two channels for humidity/temperature models). The capacitance polymer RH sensor and solid state band gap temperature sensor are temperature compensated. Enclosure is aluminum with NEMA 4X (IP66) rating, 1/2" female NPT conduit connection. Approvals include FM explosion-proof (Class I Div. 1 Group B, C, D; Class II Div. 1 Group E, F, G; Class III Div. 1) or FM intrinsically safe (Class I Div. 1 Group A, B, C, D; Class II Div. 1 Group E, F, G; Class III Div. 1 T4).