Ozone sensor, calibration and Sketch

Other Hardware Sensors
1

Hello guys, I'm quite new in Arduino and I'm having some trouble with my ozone sensor. Well, let's to the point.

I'm working with the Ozone sensor model Mq-131 and one module KS123-35Y500K in an Arduino UNO.
However, I don't know how to calibrate this sensor to get an accurate measure, as well as how to write a sketch that returns me an answer in units of parts per million (ppm). Could you help me with this?

Greetings!

Some extra information

My Wiring:

My Arduino Sketch

int sensor_AOUT = A1; //connected from AOUT to the sensor to A1 on the Arduino 
int sensor_DOUT = 2; //connect DOUT from sensor to Arduino pin 2 
int wartosc_AOUT; //variable for the value of AOUT 
int wartosc_DOUT; //variable for the value of DOUT 
 
void setup() { 
 Serial.begin(9600); //start the monitor serial port 
 pinMode(2, INPUT); //set pin 2 as input 
 
} 
 
void loop() { 
 
 wartosc_AOUT = analogRead(sensor_AOUT); //load values from AOUT 
 wartosc_DOUT = digitalRead(sensor_DOUT); //load values DOUT 
 
 Serial.print("D0: "); //display on serial monitor 
 Serial.print(wartosc_DOUT); 
 Serial.print(" -- A0: "); 
 Serial.println(wartosc_AOUT); 
 delay(200); //delay between consecutive readings 
 }

The sensor I have is the following: Link to the Sensor.

Its datasheet is the Following (I guess): https://aqicn.org/air/view/sensor/spec/o3.winsen-mq131.pdf

2

However, I don't know how to calibrate this sensor to get an accurate measure, as well as how to write a sketch that returns me an answer in units of parts per million (ppm).

The measurement range is below 1ppm, so ppb (parts per billion) is probably a better output unit.

I'm working with the Ozone sensor model Mq-131 and one module KS123-35Y500K in an Arduino UNO.

A link to that board would help.

This library makes the conversion to ppb. Remember the conversion of the read analog value is also based on the humidity of the air around the sensor as well as the type of sensor (there are two versions named MQ131), so this sensor for itself won't return accurate results.

If you want to actually calibrate the sensor you must have a controlled ozone environment which is probably outside the possibilities of a hobbyist.

3

Pylon, Thanks for Answering me! I've edited the original post with some additional information to improve the question! :slight_smile:

4

The MQ series of inexpensive sensors are not useful for making accurate measurements.

They all respond to several gases, and even if calibrated, the output tends to drift with time and other factors.

In general, the sensors can only report that something in the environment has changed.

5

Hey @jremington! What sensor would be the better choice to measure ozone concentrations in the air? Do you have some suggestions? Fair prices would be appreciated :slight_smile: