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Calibration and MQ135 Library

A project log for Handheld AirQuality Detection and Wireless NODE

Using an Arduino and a LCD Display. Determines air quality with detachable wireless sensor and uses Recycled parts

joedefajoedefa 05/09/2015 at 15:351 Comment

The hardest part of this project was calibration. While working on calibration I had found a great contributor of the Sniffing Tricket by Georg Krocker. In his project he details how to calibrate the sensors and also gives a GREAT library for the MQ135. https://github.com/GeorgK/MQ135

Discussions

Jackson96 wrote 06/11/2018 at 05:11 point

Hi do you know how the author get these values from? 

#define RZERO 76.63

/// Parameters for calculating ppm of CO2 from sensor resistance

#define PARA 116.6020682

#define PARB 2.769034857

/// Parameters to model temperature and humidity dependence

#define CORA 0.00035

#define CORB 0.02718

#define CORC 1.39538

#define CORD 0.0018

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