Extech 42275 Temperature and Humidity Datalogger with RS232 Computer Interface Records up to 16,000 readings Program sampling rate from 1 second to 2 hours Program the logger and download data using Windows? 95/98/2000/NT/ME/XP compatible software Real time clock stores the time and date with data Range: 0 to 100% RH , -40 to 185?F (-40 to 85?C)