Series HHT Hazardous Area Humidity/Temperature Transmitter
Intrinsically Safe or Explosion-Proof Models
The SERIES HHT Hazardous Area Humidity/Temperature Transmitter takes accurate measurements in the harshest of environments. The explosion-proof model is offered with 4 to 20 mA output for humidity only. The intrinsically safe version is offered with 4 to 20 mA output for humidity and temperature, and do require an intrinsically safe barrier to meet hazardous area approvals. It is important to develop a routine schedule for replacing the RH/temperature sensor (part number A-451). The sensor should be replaced annually or sooner depending on application conditions.
- Process monitoring
- Offshore HVAC monitoring
- Dust and grain handling
- Relative Humidity Range: 0 to 100% RH.
- Temperature Range: -40 to 140°F (-40 to 60°C).
- Accuracy: ±2% 10 to 90% RH, ±0.9°F at 72°F (±0.3°C at 25°C).
- Hysteresis: ±1%.
- Repeatability: ±0.1% typical.
- Temperature Limits: -40 to 140°F (-40 to 60°C).
- Storage Temperature: -40 to 176°F (-40 to 80°C).
- Compensated Temperature: -40 to 140°F (-40 to 60°C).
- Power Requirements: For instrinsically safe models HHT-IX, 9.5 to 28 VDC. For explosion-proof models HHT-EX, 16.5 to 28 VDC.
- Output Signal: 4 to 20 mA, 2 channels for humidity/temperature models (loop power on RH).
- Response Time: 15 s.
- Electrical Connections: Screw terminal block.
- Conduit Connection: 1/2″ female NPT.
- Drift: <1% RH/year.
- RH Sensor: Capacitance polymer.
- Temperature Sensor: Solid state band gap.
- Housing Material: Aluminum.
- Display: Optional 2 line alpha numeric, 8 characters/line. Temperature display is °F/°C selectable.
- Display Resolution: RH: 0.1%; Temperature: 0.1°F (0.1°C).
- Weight: 2 lb 8 oz (1134 g).
- Enclosure Rating: NEMA 4X (IP66). Models HHT-EX: FM Explosion-proof, Class I Div. 1 Group B, C, D, Class II Div. 1 Group E, F, G, Class III Div. 1; Models HHT-IX: FM Instrinsically Safe, Class I Div. 1 Group A, B, C, D, Class II Div. 1 Group E, F, G, Class III Div. 1 T4.
- Agency Approvals: FM, CE.
Models & Ordering