This DataLogger measures and stores up to 32,000 humidity (0 to 100%RH) and temperature (-35 to 80℃(-31~176°F)) readings. Dew point and more professional applications can be provided by the PC software DGraphTM. Logger status, alarm indication and low battery indication are via flashing red/green. LED and yellow LED. The button on housing can be used to start logging, or confirm and clear LED alarm when LED alarm is hold status.