Measuring Air Quality in a DIY Underground Mine

People have asked about air quality when digging tunnels at Sandland (the hobby mine that I help with occasionally). I added some air sensors to my homemade tricorder sensor and took it down for a day of digging to find out!

Sensors I'm using:
Nova PM SDS011 Dust Sensor
CJMCU-811 CO2 sensor

The main thing we worry about is silica sand and dust from the Jordan Sandstone that we're excavating. Airborne sand is a known health hazard, so we make sure to use respirators when digging.

Using the Nova PM with a Raspberry Pi: https://hackernoon.com/how-to-measure-particulate-matter-with-a-raspberry-pi-75faa470ec35

https://www.raspberrypi.org/blog/monitor-air-quality-with-a-raspberry-pi/

Using the CO2 sensor with a Pi: https://www.makerblog.info/cjmcu-811-with-raspberry-pi.html

One thing to note is that the CO2 module needs a lower I2C baud rate than standard. This didn't seem to affect my other I2C devices.