Extech Instruments will showcase its new humidity and temperature chart recorder, Model RH520. The paperless chart recorder is said to be easy to set up and operate. The unit may be desk or wall mounted and provides simultaneous numerical and graphical displays of humidity (20 to 95 percent rh) and temperature (-20 to 140 degrees F), the manufacturer says. The RH520 also calculates dew point.

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