* Power supply from generator (battery is no need) or DC 9V battery. * Humidity meter/%RH : 10 to 95 %RH. * Humidity meter/Temp. : 0 to 50.0 oC, oC/oF. * Type K Thermometer : -100 oC to 1300 oC. * Data hold, Record (Max., Min.). * Patented.