Gas sensor calibration for PPM output

Forum 2005-2010 (read only) Hardware Interfacing
1

Hi guys,
I have bought this MQ7 (http://www.seeedstudio.com/depot/electronic-brick-carbon-monoxide-sensormq7-p-470.html) sensor brick and I want to connect it on Arduino for transmitting the PPM values on Pachube.com feeds. I can read the values from analogPin but can I convert it in ppm?
Remember that the brick have a little pot for voltage control, but I cannot calibre it?

Thanks

2

You need the data sheet for the sensor itself.
http://www.hwsensor.com/English/PDF/sensor/MQ-7.pdf

There you will find the calibration data. Looking at the board the sensitivity control only turns the sensor output down so turn it up fill. Then what you read in the analogue input is 5/1024 volts per step so you can do the calibration from the graphs given in the data sheet.

3

Many many THANKS!

4

i would like to construct with my arduino a Gas sensor, can anyone help me wiyh the program and wiyh conections between arduino and MQ7 sensor? thanks!