TGS 4161 CO2 SENSOR

MIMG · **Joined:** Tue Mar 22, 2011 4:49 pm **Posts:** 35

Hi everyone,

We have the same problems of interpretation with CO2 gas. In datashet the graphic show difference between EMF1-EMF2.

We have readen that EMF1 is measured in 350ppm CO2 and it dues change between 220 and 490mV, how we can know the correct value?

The sensor TGS is measuring EMF2??It is because we obtain differences of 220mV and in datasheet puts that it should be between 44 and 72mV,

Could you help us?

libelium-dev · **Joined:** Mon Sep 28, 2009 1:06 pm **Posts:** 7818

Hi MIMG,

what you should take into account for your measurement is the difference between the voltage reference (EMF1, voltage at a concentration of 350ppm) and the read voltage. This value is the variation of the electromotive force that you have to check in the graph to get the gas concentration.

The way to get a more exact value of the EMF at 350ppm is calibration. If you don't need a great precision you can suppose this voltage as that measured in air, but if you want an accurate measurement you will ahve to calibrate the sensor.

Regards.