Pseudo WBGT Feeling Temperature Measurement
- Raspberry Pi
- IchigoJam
- Sensirion SHT31, SHT30
WBGT; Wet Bulb Globe Temperature is one of the internationally standardized heat indexes.
The value is in degrees Celsius, making it an easy-to-understand index. However, a special measuring device called a wet bulb globe thermometer is required to measure it.
There is also a simpler method of measuring it, which is created by the Japanese Society of Biometeorology (日本生気象学会), and estimated it from temperature and humidity. But, since there was no data below 20°C in the published table.
So, I also used data from the other WBGT estimation formula derived from meteorological data for six cities by Masashi Ono of the National Institute for Environmental Studies (国立環境研究所).
The pseudo WBGT formula I created for indoor use is:
WBGT = 0.725*Ta + 0.0368*RH + 0.00364*Ta*RH – 3.246
- How to Make it on Raspberry Pi (Google Translation)
- How to Make it on Raspberry Pi in Japanese
- MIT LICENSE
Connect an I2C interface of M5Stack ENV II or III Unit to the GPIO header pins on your Raspberry Pi.
Which is used the bc command. It's useful for calculations on a Linux-based OS such as Raspberry Pi. You can get a WBGT value to substitute temperature for the variable TMPL and humidity for HUM, and execute the following command.
echo "0.725 * ${TMPL} + 0.0368 * ${HUMI} + 0.00364 * ${TMPL} * ${HUMI} - 3.246"|bcExample:
pi@raspberrypi:~ $ TMPL=28
pi@raspberrypi:~ $ HUMI=90
pi@raspberrypi:~ $ echo "0.725 * ${TMPL} + 0.0368 * ${HUMI} + 0.00364 * ${TMPL} * ${HUMI} - 3.246"|bc
29.53880- Author's Web Page: https://bokunimo.net/
- Blog Page: https://bokunimo.net/blog/
- GitHub Pages site: http://git.bokunimo.com/