There is no specific standard that applies to heat stress. The only citation option is a General Duty, 5(a)(1).
- The wick of the natural wet bulb thermometer should be kept wet with distilled water for at least one-half hour before the temperature reading is made. It is not enough to immerse the other end of the wick into a reservoir of distilled water and wait until the whole wick becomes wet by capillarity. The wick must be wetted by direct application of water from a syringe one-half hour before each reading.
- The wick should always be clean, and new wicks should be washed before using.
- The globe thermometer should be exposed at least 25 minutes before it is read.
- A stand should be used [. . .] so that [. . .] the wet-bulb and globe thermometer are not shaded.
- Wet Bulb Globe Temperature Indexes (WBGI): Here is some information on how the different temperature indices are calculated. This will help to understand the differences between the various readings on the heat monitor:
- Indoor or outdoors with no solar load: WBGT = 0.7NWB + 0.3GT
- Outdoors with solar load: WBGT = 0.7NWB + 0.2GT + 0.1DB
- WBGT = Wet Bulb Globe Temperature Index
- NWB = Natural Wet-Bulb Temperature
- DB = Dry-Bulb (air) Temperature
- GT = Globe Thermometer Temperature
[Honestly, I'm not sure which of these we need to enter on the sampling sheets. I have yet to find anything in IMIS or a CPL that indicate which IMIS codes to use. -kbh]
8320 Heat Stress - Dry
- Do not use anything involving the Wet Bulb (WB)
8330 Heat Stress
- The IMIS description indicates that this is for inside heat monitoring. Therefore, use the WBGTi value. [???]
8891 Humidity, Relative
NEEDS INFORMATION ON QUESTEMP 34