EXTECH RH490 - Precision HYGRO-Thermometer with GPP (Grains per Pound)
Product Description
EXTECH RH490 - Precision HYGRO-Thermometer with GPP (Grains per Pound)
- High-Accuracy Humidity Readings – Measures relative humidity from 0 to 100% with ±2% accuracy and 0.1% resolution—ideal for critical HVAC, restoration, and lab monitoring.
- Simultaneous Dual Backlit Display – View humidity or water vapor (GPP or g/kg) alongside temperature, dew point, or wet-bulb readings—enhanced clarity in any lighting.
- Fast 30-Second Response – Rapid humidity stabilization ensures timely, reliable data even in dynamic environments.
- Convenient Data-Hold & Min/Max Functions – Hold fluctuating readings or review peak/minimum values; plus auto power-off with disable and low-battery alert for long battery life.
- Slim, Ergonomic Design – Rubberized sides ensure a secure one-hand grip; includes carrying case and 9V battery for field-ready portability.
Featuring a slim design with rubberized sides for better grip, the Extech RH490 is specifically designed for HVAC and water damage restoration contractors. This meter measures Temperature (-22 to 199 degrees F/-30 to 100 degrees C), Humidity (0 to 100 percent RH), Dew Point (-22 to 199 degrees F/-30 to 100 degrees C), Wet Bulb (32 to 176 degrees F/0 to 80 degrees C), and Mixing Ratio in GPP (grains per pound/grains per kilogram) 0 to 1120 GPP/0 to 160g/kg.
Other FeaturesLess than 30 second RH response time with 2 percent RH accuracy, dual backlit LCD display, Data Hold, Min/Max, Auto Power Off (with disable), and low battery indicator.
What's in the BoxComplete with carrying case, 9-volt battery, and user manual
More Extech Instruments to Choose From View larger RH390 Dual Display Hygro-Thermometer Psychrometer
Precision meter measures relative humidity from 0 to 100 percent with an accuracy of ±2 percent RH and Temperature from -22 to 199 degrees F (-30 to 100 degrees C) with an accuracy of ±1.8 degrees F/1 degrees C. Capacitance RH sensor provides a response time of less than 30 seconds. The dual backlit display of Temperature and Humidity can be switched to show Humidity and Dew Point (-22 to 199 degrees F/-30 to 100 degrees C), or Humidity and Wet bulb (32 to 176 degrees F/0 to 80 degrees C). Slim design with rubberized sides provides improved grip. Other features include data hold, Min/Max record, auto power off and low battery indicator. Comes with carrying case, 9-volt battery, and user manual.
View larger HD500 Psychrometer with Infrared ThermometerPsychrometer features an InfraRed Thermometer for non-contact temperature measurement -58 to 932 degrees F (-50 to 500 degrees C) with 30:1 distance to target ratio. A built-in laser pointer identifies the target area and improves aim. A Type K Thermometer measures air and contact surface temperature from -148 to 2501 degrees F (-100 to 1372 degrees C). Additional measurements include: Relative Humidity (0 to 100 percent RH), Dew Point (-90.4 to 140 degrees F/-68 to 60 degrees C), and Wet Bulb (-6.88 to 140 degrees F/-21.6 to 60 degrees C). Measurements are displayed on a large triple LCD backlit display. Heavy Duty rugged double molded housing. Auto Power Off conserves battery life. USB port includes software. Comes with Windows compatible software with cable, Type K bead wire temperature probe, hard carrying case, 9-volt battery, and user manual.
