The GT-D is a precise and long-term stable temperature sensor (NTC) designed for duct installation. Placing sensors within ducts is often cost-effective and also provides protection against tampering.

The sensor can also be ordered as the GTN-D, which is a simplified version intended as an accessory for room temperature control via the SBTb thermostat actuator controller.

Functionality

• GT-D: The temperature sensor, housed in an enclosure with an insertion tube for duct mounting, converts the NTC resistance into a 0-10 V output signal for the temperature range of 12-43ºC.
• GTN-D: This sensor has the same housing as the GT-D but is a passive NTC sensor without conversion to an active output signal.

Short Time Constant

NTC resistors have a time constant of approximately 3 minutes in flowing air. When the temperature sensor is placed in the exhaust duct, temperature measurement may not be optimal if the ventilation flow is at a very low level. However, this is not an issue when ventilation is increased during occupancy. A sensor placed on a wall can be negatively affected by the wall's temperature, extending the time constant (up to 30 minutes in the case of concrete pillars or similarly slow-reacting materials).