The RHT20 is a Humidity Temperature Datalogger which records up to 16,000 Humidity and 16,000 Temperature readings with a user programmable sample rate. USB interface for easy setup and data download. Selectable data sampling rates from 1s to 24hr. User-programmable alarm thresholds for RH and Temperature. LCD displays current temperature and humidity readings plus Min/Max and Alarm status. Long battery life.