Extech RH300 Digital Psychrometer

Extech RH300 Digital Psychrometer


The Extech Digital Psychrometer calculates T1-T2 differential (air temperature minus external probe temperature).


  • Wet bulb measurements without slinging
  • Switchable °F/°C temperature units with 0.1° resolution
  • Data hold freezes current reading on display
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The Extech Digital Psychrometer simultaneously displays % relative humidity, temperature, dew point, or wet bulb or probe temperature. The wet bulb measurements are made without slinging. The meter calculates T1-T2 differential (air temperature minus external probe temperature) using optional probe and T2-dew point. The unique sensor cap design twists to the closed position for protection during storage. Additional meter features include switchable °F/°C temperature, data hold, max/min readings, and automatic power off.

Notable Specifications:
  • Humidity range: 10 to 90%RH
  • Humidity maximum resolution: 0.1%RH
  • Humidity basic accuracy: ±3%RH
  • Temperature (internal) range: -4 to 122°F (-20 to 50°C)
  • Temperature (internal) maximum resolution: 0.1°
  • Temperature (internal) basic accuracy: ±1°F or ±0.6°C
  • Temperature (external) range: -4 to 158°F (-20 to 70°C)
  • Temperature (external) maximum resolution: 0.1°
  • Temperature (external) basic accuracy: ±1°F or ±0.6°C
  • Dew point range: -90.4 to 122°F (-68.0 to 49.9°C)
  • Wet bulb range: -6.9 to 122°F (-21.6 to 49.9°C)
  • Dimensions: 7 x 1.9 x 1" (178.5 x 48.4 x 24.7mm)
  • Weight: 3.3oz (95g)
What's Included:
  • (1) Digital Psychrometer
  • (2) AAA batteries
Image Part # Product Description Price Stock Order
Extech RH300 Digital Psychrometer RH300 Digital Psychrometer
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Extech RH300 Digital Psychrometer RH300-NIST Digital Psychrometer, NIST traceable
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Extech RH300 Digital Psychrometer RH305 Digital Psychrometer Kit
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Extech RH300 Digital Psychrometer RH305-NIST Digital Psychrometer Kit, includes NIST Certificate
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Image Part # Product Description Price Stock Order
Extech RH300-CAL Calibration Kit RH300-CAL Calibration kit for 445715 & 445815
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Extech TP890 Thermistor probe for RH300
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