Tiny Sensors Measure RH

Relative humidity (RH) levels of from 20% to 90% (10% to 90% optional) can be measured using new sensors housed in a translucent, rectangular, polypropylene package. The 7.0 x 4.0 x 10.5-mm high package is perforated to allow air to flow into the unit and contains a moisture-repellant, precision-resistive membrane element that is sensitive to humidity. Electrically, HIS-06 Series sensors change resistance (impedance) in response to surrounding changes in humidity, with settling time occurring within 3.5 minutes. The proportional changes in resistance, in turn, permit a simple external circuit to be used to monitor the changes. Operating temperature range is -20°C to 60°C. Well-suited for use in various consumer and commercial RH monitoring applications, HIS-06 Series sensors have radial leads, can withstand 320°C soldering temperatures, and have a starting price of $5.20 each in small quantities. More details are available from HDK AMERICA INC., Barrington, IL. (847) 382-9411.