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Temperature/Humidity/Dew Point Sensor

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The GTHD/GT3HD Sensors provide real-time temperature, humidity and dew point data back to the host unit for data logging and alarming. These sensors can be daisy chained using the Remote Sensor port or another sensor can be added to this port. The GTHD and GT3HD sensors are the same with the T3HD having two additional RJ12 ports for adding remote temperature (RT) sensors. GTHD/GT3HD sensors are connected to host unit with provided RJ12 patch cable. Add up to 16 sensors per host unit for most platforms. The enclosure is designed for easy mounting nearly anywhere using screws or adhesive. 

The GTHD is especially useful for watching out for rapid temperature drops and/or high humidity that can cause condensation to form on electronic equipment, resulting in hardware corrosion and component failure.  Electrostatic discharge is likely to occur at low relative humidity levels, which can severely damage sensitive IT equipment.  Based on ASHRAE’s recommended humidity range for IT equipment, we suggest setting relative humidity alarm thresholds for when the value exceeds 55% or falls below 40%, however each facility is unique and may require varied ranges.



  • RJ12 port for daisy-chaining sensors
  • RJ12 port for connecting to host
  • On-board sensors:
    • temperature: /- 0.5C at 25C
    • humidity: accurate within 3%
    • dewpoint: accurate within 4%
  • Additional remote temperature sensor ports for expansion (T3HD only)



  • GTHD Sensor
  • RJ12 Patch Cable (10’ or 50’)


  • GT3HD Sensor
  • RJ12 Patch Cable (10’ or 50’)
  • Remote Temp Sensor (3’ cable)
  • Remote Temp Sensor (6’ cable) 
GT3HD and GTHD measure temperature,
humidity and dewpoint in one location.

GT3HD includes external temperature
sensors for monitoring two additional

GT3HD and GTHD can be daisy-chained,
simplifying multiple cabinet monitoring. 





Installation: Mount the GTHD/GT3HD so that a hazardous condition is not achieved due to
uneven mechanical loading.

Wiring: Use provided patch cables to connect GTHD/GT3HD sensors to host unit.

Calibration: GTHD/GT3HD sensors are factory calibrated.



• Temperature Range: -4 °F to 176 °F (-20 °C to 80 °C) /-0.5 °C
• Humidity: 5% to 95%, /-3%
• Dew point: -58 °F to 185 °F (-50 °C to 85 °C)

Physical Dimensions
Width - 3.90" (9.91cm)
Length - 1.71" (4.34cm)
Depth - 0.94" (2.39cm)
T3HD Weight - 1.2oz (34.0g)
THD Weight - 1.1oz (31.2g)

Compliance RoHS 






Download GT3HD brochure     |      Downlod GTHD Brochure


ITWatchDogs warrants that GT3HD/GTHD sensors will be free of defects
for 1 year from the date of purchase. 

Buy the GTHD 10 ft sensor Online G1331:


Buy the GTHD 50 ft sensor Online G1546:

Buy the GT3HD 10 ft sensor Online G1332:


Buy the GT3HD 50 ft sensor Online G1547:

USA Office

Address: 1480 Gulf Road, Suite 837,
PO Box 1280
Point Roberts, WA 98281

Western Canada - Vancouver BC

Tel:1.800.663.6001 or 1.604.925.6150
Address: 2454 Haywood Ave
West Vancouver, BC V7V 1Y1

Eastern Canada - Markham, Ontario

Tel:1.800.465.0164 or 1.905.513.7027