Heat Index Monitor with 35 x 40mm Brass Black Ball


Heat Index Monitor with 35 x 40mm Brass Black Ball

The #WBGT8758 heat index monitor is ideal for industrial uses (such as HVAC/R) and outdoor sports medicine applications. An optional hardware/software kit turns the instrument into a data logger.


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  • Measures and displays the ambient temperature, relative humidity (RH), and the dew point and wet bulb temperatures
  • Audible alarm with adjustable setpoint
  • 33% and 75% #HR33LJ and HR75LJ reference salts are available to calibrate RH measurements in the field
  • Auto power off (can be disabled for calibration)
  • Optional #ASFTKIT PC data logging software/hardware is available
  • Tripod mount
  • NIST calibration is available
  • Specifications


    • Ambient temperature measurement range/accuracy: 32° to 122°F (0° to 50°C)/±0.8°F (±0.6°C)
    • RH measurement range/accuracy: 0 to 100%/±3% of reading from 10 to 90%RH; ±5% elsewhere in range
    • Wet bulb temperature measurement range/accuracy: 70° to 115°F (21° to 45°C)/±2°F
    • Dew point temperature measurement accuracy: ±3% of reading
    • Black ball dimensions: 1.38 (H) x 1.57 (Diameter) in. (35 x 40 mm)
    • Audible alarm setpoint range: 68° to 99°F (20° to 37°C)
    • Auto power off: After 20 minutes of inactivity
    • Power source: Two "AAA" batteries (included)


    • Batteries
    • 1-year limited warranty


    • 10 x 1.6 x 1.9 in. (254 x 40 x 49mm)


    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 a heat index?

    The heat index (HI) or humiture or humidex (not to be confused with the Canadian humidex) is an index that combines air temperature and relative humidity, in shaded areas, as an attempt to determine t...
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    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 www.P65Warnings.ca.gov.