Extech RH520A-240 Humidity Plus Temperature Chart Recorder 240V with Detachable Probe Graphical datalogger for Humidity/Temperature measurements and Dew Point calculation Simultaneous numerical and graphical display of Humidity and Temperature readings, plus Time and Date Measures Humidity (10 to 95-Percent RH) and Temperature (-20.0DegreeF to 140.0DegreeF) plus calculates Dew Point Basic accuracy 3-Percent RH, 1.8DegreeF/1DegreeC Large dual graphical LCD displays with adjustable vertical and horizontal TAC resolution