Hid TEMPerHUM thermometer & hygrometer is a measurement device using USB port to connect to a computer or other machines. It can measure the temperature and the humidity of the machine and the environment accurately and can calculate the dewpoint automatable. It must be connect to the computer to start working .Hid TEMPerHUM can be use in computer room, weather, environment and special environment temperature and humidity testing. Function & Feature Range of temperature: TEMPerHUM -40~ + 120 C; -40~ + 248F; Resolution rate of temperature: 0.06C Precision of temperature: + 2C; Range of humidity: 0~ 100RH% Resolution rate of humidity: 0.03RH% ; Precision of humidity: + 5 RH% 20RH% ~ 90 RH% ; Voltage: 4~ 6V; Electricity: < 10 mA; Signal indication: Red light when working Support Windows NT, XP, VIST; Memory requirement: 20M Data autosave to be txt Or csv format, can be open by excel; Send mails function Graph transfer function