The Extech RH350 dual input hygro-thermometer psychrometer features two Type K external probe inputs for superheat measurements. It calculates superheat differential: T1-T2, Air-T1, and T1-Dew Point. The backlit LCD displays three parameters simultaneously: %RH and temperature with either dew point, wet bulb, or Type K temperature.

Memory stores up to 99 data points. A built-in RS-232 interface allows data download to a PC using Windows Hyperterminal. Additional features include MAX/MIN with time stamp, AVG, and data hold. Ideal for HVAC technicians requiring superheat calculations and comprehensive environmental measurements.