Dwyer Instruments” Series WHP Wireless Humidity/Temperature Sensors use a 418 MHz transmitter to transmit data up to 100 feet without the use of a repeater. When coupled with a receiver and output module, the Series WHP can output voltage, current or resistance values for humidity and temperature. Since the unit is battery powered using two AA batteries, users can change the location of the sensor by a couple of feet or to a different wall without worry about extra labor cost. With the transmit rate at approximately one reading every 10 seconds, the battery is estimated to last five to eight years. The duct mount and outside air sensors come standard with sintered filters to protect the sensor particulates. Setpoint adjustment and/or manual override buttons are available on wall-mount sensors.