MQ3 sensor

Hello,

I'm using the mq3 sensor and i want to calculate the load resistance (Ro) and sensor resistance (Rs) using the arduino code.

thanks

First of all you need to calibrate these sensors and after the calibration is successful with a given RL load you can read the analog MUX anytime with the routines , here is a great example of calibrating and reading for various gases like LPG, smoke etc >> http://sandboxelectronics.com/store/images/SEN-000004/SEN-000004_Source.php

Also please try to understand the datasheet and get the minimum value of clean air at a given RL in the datasheet to help in calibration.

hello, i try this code, but i don't unerstand how i can find the points for alocohol ?

float LPGCurve[3] = {2.3,0.21,-0.47};

i use 1 kohms like a load resistance and i want to calculate the amount of alcohol in % not in ppm.

For the calibration i use diffrent solutions with differents concentrations of alcohol 1%..5%. If i use alcohol the code will be the same ?

thanks