How to convert sensor readings to PPM?

Projects Programming
1

Hi guys! I have a CO2 sensor that has an analog output voltage of 0-4V which corresponds to 0-2000 PPM.

How can I display the Correct PPM units? Im getting around 1.15V as the lowest value? How can I get around 400PPM?

Pls help

2

4V = 2000PPM
1,15 = X

X = (1,15 * 2000) / 4 = 575 PPM.

Do you have another instrument, preferably calibrated, to verify how much CO2 you actually have?

3

No I dont have one. How is that formula youve given, translated into arduino code? Pls supply pseudo code sir.

4

It already is pseudo code

5

vmandin:
Hi guys! I have a CO2 sensor that has an analog output voltage of 0-4V which corresponds to 0-2000 PPM.

How can I display the Correct PPM units? Im getting around 1.15V as the lowest value? How can I get around 400PPM?

Pls help

The map() function is your friend.
So something like this should work:

rawReading = analogRead(sensorPin);
ScaledReading = map(rawReading, 0, 820, 0, 2000);