# Gas

The SimpleIndustry can be fitted with sensors that monitor the **concentration of gas** in the air in ppm. As of now, we support monitoring CH4 concentration and CO2 is being prepared.

***How to test a CO2 sensor?***

In case you wish to test the CO2 devices to check if they are reporting CO2 threshold alert messages, before the field deployment, follow the steps mentioned below.

1. Arm/activate the device via a short press using a magnet.
2. Once you have received the Start of Arming (6510) and Armed messages (6511), place the device in a box/container with no fresh air flow possible when closed.  
3. Try to breathe in some air(CO2) in the box/container and then close it with a lid, now we wait for Threshold alert messages.
4. The Gas Sensor Measuring interval is set to 5 minutes and Threshold A & B are set to 1500ppm and 3000ppm respectively.
5. When the CO2 level changes about the thresholds set, we receive an alert as such, along with the CO2 levels appended. 

| D3 | Gas below A threshold - alert 1 |
| -- | ------------------------------- |
| D4 | Gas above A threshold - alert 1 |
| D5 | Gas below B threshold - alert 2 |
| D6 | Gas above B threshold - alert 2 |

For example- 65D50961 

*65- Gas mode*\
*D5- Gas below threshold B*\
*961-2401 ppm*

65D3039D

*65- Gas mode*\
*D3- Gas below threshold A*\
*39D- 925 ppm*