Hand-held Digital Hygrometer is a battery operated instrument that measures both percent relative humidity from 0-100% with +/-2% accuracy and temperature in °F or °C with +/-0.54° F accuracy.Calculates the dew point temperature and wet bulb temperature based on the relative humidity and temperature readings.Sensing probe wand allows for more ergonomic probing of hard to reach sampling areas.Includes one 9 volt alkaline battery.