The Extech 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. Dew Point indication via the included Windows-compatible software. Selectable data sampling rates of 2s, 5s, 10s, 30s, 1m, 5m, 10m, 30m, 1hr, 2hr, 3hr, 6hr, 12hr, and 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. Place or mount the datalogger in monitoring location (storage bin, truck, cargo hold, freezer, temperature-controlled room, etc.). Datalogger records temperature and humidity at sample rate set by user. Connect the datalogger to your PC via the USB interface to retrieve readings. Datalogger displays the current Humidity and Temperature plus Min/Max and alarm status so it can be viewed anytime during the recording process.