Calibratable 4-Function Digital Psychrometer

ITEM # EP8709

Calibratable 4-Function Digital Psychrometer

The #EP8709 is ideal for measuring any environment’s ambient temperature, relative humidity (RH), and dew point and wet bulb temperatures.


Best For:



  • Displays the relative humidity (RH) above the ambient, dew point or wet bulb temperature on a backlit dual-readout LCD
  • Min/Max memory + data hold
  • 33% and 75% #HR33 and HR75 reference salts are available to calibrate RH measurement in the field
  • °F/°C switch
  • Auto power off (can be disabled for calibration)
  • NIST calibration is available
  • Specifications


    • Temperature measurement range/resolution: 14° to 122°F (-10° to 50°C)/0.1°
    • Temperature measurement accuracy: ±1.8°F (±1°C)
    • RH measurement range/resolution: 0 to 99.9%/0.1%
    • RH measurement accuracy: ±3% from 5% to 95% RH
    • Response time: <80 seconds
    • Auto power off: After 20 minutes of inactivity
    • Display size: 1.7 in. (43mm) diagonal
    • Weight (without battery): 3.77 oz. (107g)
    • Power source: "9V" battery (included)


    • Sensor protection cap
    • Battery
    • 1-year limited warranty


    • 7.56 x 2.40 x 1.57 in. (192 x 61 x 40mm)


    Which models of temperature/humidity meters are calibrateable?

    The following models have a calibration feature: EP8703, EP8706, EP8709, EP8710, LRTH185DL, LRTH185DL1, WBGT8758, WBGT8778, DTH3007SD, RHMG650, RHMG700DL

    My instrument is calibrateable. Do I need any additional accessories to perform the calibration?

    Some instruments do require a 33% and 75% salt bottle to perform the calibration. The following models use the HR33 and HR75 bottles: DTH3007SD, EP8703, EP8706, EP8709, EP8710, LRTH185DL, LRTH185DL1, ...
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    What is Dew Point?

    In simple terms, the dew point (dew point temperature or dewpoint) is the temperature at which a given concentration of water vapor in air will form dew. More specifically it is a measure of atmospher...
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    What is Wet Bulb?

    The wet-bulb temperature is the temperature a parcel of air would have if it were cooled to saturation (100% relative humidity) by the evaporation of water into it, with the latent heat being supplied...
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    What is a psychrometer?

    A psychrometer is an instrument that measures both the wet bulb and dry bulb temperatures.

    Prop 65

    ⚠ WARNING: This product can expose you to chemicals including di2-ethylhexylphthalate (DEHP), which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to