!!. The sensor you use isnt suited for (exact) school experiments..
- It needs constant heatup ( 48 hrs contant power to heater)
- Sensor is sensitive to many gases in addition to methane! Even breath will change output
- Its extremly difficult to calculate correct ppm levels (advanved math)
................
bottom line
students should be able to explain:
- the physics of sensor
- maybee also the chemistry that takes place when gas is present ?
- the principals for detecting theese changes with a computer
- how electronics is suitable for this task
- factors to be aware of -temperature, humidity, other gases, tolerance of componets and so on.
I , nor my students, have ever got reliable readings from a variete of MQ... sensors (many)
The important part is, to me, the understanding of the principal.
Knut N, Norwy