How do you use a WBGT meter?
The meter measures WBGT index with (IN) or without (OUT) direct sun exposure. Hold down the MODE/▲ for more than 1 second to alternate between settings. The IN or OUT icon will appear in the display. The HT30 has a user settable heat stress alarm.
How do you calibrate a WBGT?
Plug the sensor probe into the 75 % calibration salt bottle. Press the power button for 2 seconds to start until blinking “7X. X % ” displays on the screen.” Meter will finish calibrating in about 60 minutes (1 hour) or when the value stops blinking.
How is outdoor WBGT calculated?
The wet bulb globe temperature (WBGT) is calculated by using the following equations.
- For outdoors with direct sun exposure: WBGT = 0.7 x Tempwet bulb + 0.2 x Tempglobe + 0.1 x Tempair
- For indoors or outdoors without direct sun exposure: WBGT = 0.7 x Tempwet bulb + 0.3 x Tempglobe
What is black globe temperature?
Among the meteorological variables, the black globe temperature is considered for the calculation of many heat stress indices. One of the most common and widely used indices to assess heat stress in the workplace, which requires measuring the black globe temperature, is the wet-bulb globe temperature (WBGT).
What causes the heat index?
When the atmospheric moisture content (i.e. relative humidity) is high, the rate of evaporation from the body decreases. In other words, the human body feels warmer in humid conditions. The opposite is true when the relative humidity decreases because the rate of perspiration increases.
How does the ht30 heat stress WBGT meter work?
The HT30 has a user settable heat stress alarm. When heat stress WBGT readings reach the level set by the user, the HT30 will emit an audible alarm, and will continue to do so until the temperature falls below the set threshold.
How is the WBGT different from the heat index?
This differs from the heat index, which takes into consideration temperature and humidity and is calculated for shady areas. If you work or exercise in direct sunlight, this is a good element to monitor. Military agencies, OSHA and many nations use the WBGT as a guide to managing workload in direct sunlight.
What does the heat stress index ( ht200 ) measure?
The HT200 is a Heat Stress WGBT Meter which enables accurate measurements for Wet Bulb Globe Temperature (WGBT), Black Globe Temperature (TG), Humidity (%RH), Air Temperature (TA), Wet Bulb (WT) and Dew Point (DEW). Heat Stress Index measures how hot it feels when humidity is combined with temperature, air movement and radiant heat.
