Recommended Alert Limit

Description

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 table A.1). The WBGT reference limits for acclimatization from table A.1 is not used in 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.

Example

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 zone then when the individual is below 80% of the RAL
• yellow from 80-100
• red from 100 to 120%
• the highest dark red when above 120%

Right now, the app is working with the following logic

    Green  if WBGT <= 20 C
    Orange if 20  C < WBGT < 25 C and
    Red    if WBGT > 25 C

Value Set

Value	Result	Comment
WBGT <= 0.8 * RAL	Green
WBGT > 0.8 * RAL and WBGT <= RAL	Orange
WBGT > RAL and <= RAL * 1.2	Red
WBGT > RAL * 1.2	Dark Red	Not implemented yet

How does it look?

This screenshots are added to show the results as proof-of-concept this is not the final solution.

Where in the code?

• RecommendedAlertLimit.java https://github.com/frksteenhoff/ClimApp/blob/master/ClimApp/app/src/main/java/com/example/android/climapp/wbgt/RecommendedAlertLimit.java
• DashboardFragment.java https://github.com/frksteenhoff/ClimApp/blob/master/ClimApp/app/src/main/java/com/example/android/climapp/dashboard/DashboardFragment.java
• RALTest.java (testing) https://github.com/frksteenhoff/ClimApp/blob/master/ClimApp/app/src/test/java/com/example/android/climapp/RALTest.java