The Model RH401 digital psychrometer is ideal for HVACR installation and repair, mold inspection and remediation, and plant maintenance. The device features a built-in infrared thermometer, for hard-to-access surface temperature measurements. The backlit triple display enables simultaneous viewing of relative humidity and surface temperature, along with air temperature, dew point or wet bulb. The unit features a data hold and auto power off as well as a built-in RS-232 interface to capture readings on a computer.

Extech Instruments, 285 Bear Hill Road, Waltham, MA 02451; (781) 890-7440; fax (781) 890-7864; www.extech.com.