Welcome to Honeywell Sensing and Control’s product overview of the HIH-5030 and HIH-5031 Series Humidity Sensors. These humidity sensors may be used to monitor or tightly control humidity, often a requirement in many industrial HVAC applications such as air conditioning, thermostats, humidifiers/dehumidifiers, humidistats, and enthalpy sensing (measures heat density of air), and in medical applications such as sleep apnea equipment, treadmill stress monitoring equipment, and infant incubators. Honeywell has designed these sensors to accommodate battery operated applications that utilize less than a 3 volt supply voltage.