HH804U is a high accuracy RTD input thermometer. These handhelds work with platinum PT100 RTDs and are selectable for 3 different temperature coefficient curves. These units comply with ITS-90. Both come standard with a built in USB port and DC power jack. Optional Windows software and AC adapter allow real time data logging to PC for extended periods. The HH804W model features a quick and easy to use wireless interface instead of USB. This allows real time data transmission at distances of up to 75'.