The Extech RH490 hygro-thermometer is a precision hygro-thermometer specifically designed for
HVAC and water damage restoration contractors. The Extech RH490 hygro-thermometer features a
fast 30 second response time and an accuracy of ±2%. The dual backlit display simultaneously
shows humidity or water vapor in grains per pound (g/kg) along with either temperature, dew
point, or wet bulb.
The Extech RH490 hygro-thermometer features a slim, handheld design with rubberized sides for
better grip and for one hand operation. The Extech RH490 hygro-thermometer has data hold and
min/max functions as well as auto power off with disable and low battery indicator.