Breathalyzer with MQ-3 and Arduino

Hi, I’ve made a Breathalyzer with MQ-3 and Arduino and wrote a full DIY tutorial

if you guys wanna take a look:

TUTORIAL HERE:

http://www.danielandrade.net/2010/03/07/building-an-breathalyzer-with-mq-3-and-arduino/

:smiley:

Nice! It would be really cool if you could get it to give you accurate readings in numbered digits! We should work this circuit into the Openbar project!

hi

I am thinking of building something similar. Did you feel that the range of the MQ3 was enough? I am looking at the TGS 2620 which is far more sensitive and three times more expensive. Or is that overkill for alcohol testing?

thanks

fubbi

Hi guys,

I bought the MQ-3 sensor. It’s easy to read the value of the sensor with an analog pin.

BUT i have a big problem : i need to calibrate the detector for 0,4mg/L (approximately 200ppm) of Alcohol concentration in air…

How get exactly 0,4 mg/L of Alcohol concentration in air ? :-/

http://en.wikipedia.org/wiki/Blood_alcohol_content

various cryptic charts, should tell you how many beers to drink to get enlighted ;)

fubbi

Thanks for your link. I also checked http://en.wikipedia.org/wiki/Breathalyzer#Calibration but there is no DIY solution…