Converting analog value into ppm - gas sensor

Forum 2005-2010 (read only) Hardware Interfacing
1

Hi guys,

I bought this sensor MQ4
and trying to make it work. Now I can get the analog value from the sensor, but how can I convert the value to PPM?
Because I can't find any clearly formula in side the datasheet.
Could anybody help me?

Thanks

2

I googled MQ4. Over 320,000 hits.

You'll need to help narrow down that number. Provide a link to the sensor you have, or to the datasheet for the sensor.

3

I'm thinking this is the unit...

but I don't know how to interpret the datasheet either.

4

From the graph in the data sheet it looks like each type of gas has it's own curve for output vs. PPM. In any case, to get PPM, the sensor has to be calibrated.

sdf1984 - if you Google "MQ-4 gas sensor calibration" you will find more info. (The hit on the Pololu site has a suggested R value and a better datasheet.)

PaulS, you probably should have Goggled "MQ-4 gas sensor". The datasheets are the first hits. :wink: