Recommended Alert Limit
The recommended alert limit uses information about the Wet Bulb Globe Temperature and your metabolic rate in order to provide information about your situation -- are you working too hard on a hot day? etc. This is visualized for the user on a scale green/orange/red depending on whether you are working too hard in a hot condition or not.
This is calculated based on the RAL score which is given by the following equation:
RAL = 59.9 - 14.1 * log10(M)
Here, M is the Metabolic rate (W in the table below). The WBGT reference limits for acclimatization from table A.1 is not used when doing these calculations.
Each metabolic rate class has a corresponding metabolic rate value which is used in order to calculate the RAL score.
The RAL score is used together with the WBGT value in order to determine the color code for the users situation.
If the user's work lies within the metabolic rate class 2, he has the metabolic rate of 300. To calculate his RAL score 300 is input in the equation for RAL above:
RAL = 59.9 - 14.1 * log10(300) => 59.9 - 14.1 * 2.477 = ~ 25C
25C is then the RAL score.
In order to determine which color group the user is within, assuming that we have the WBGT score for the user at the current time, the following logic is used:
Green if WBGT <= 20 C
Yellow if 20 C < WBGT < 25 C and
Red if WBGT > 25 C
| Value | Description | Comment |
|---|---|---|
| default | ||
