Hygrosens KFS Series RH sensors, distributed in the U.S. by Servoflo Corp., Lexington, MA, use a capacitive polymer to measure humidity. Features include good linearity, low hysteresis, compact size, dew resistance, and stability against chemical effects. The surface-mount KFS-MSMD is 2.0 by 4.0 by 3.8 mm and offers good linearity, low temperature drift, and is suited for white goods, HVAC, automotive, and other applications that require long-term stability. The 2-pin, 3.81 by 5.0 by 0.4 mm KFS-140D is suitable for climate monitoring, HVAC, and other environmental monitoring. Temperature range is –30°C to 150°C.