Measuring pollutants is an appropriate way of ensuring by giving signs of poor ventilation and identifying specific pollutants or sources which are possible causes of indoor air quality problems. It can be expensive to test several pollutants and may require consulting the state of local health department or professionals with experience in solving indoor air quality problems.

This device was created using an Arduino in order for the program to respond to the overall gas levels for different horrible pollutants which include formaldehyde, methane, ethanol and a group of other volatile organic compounds. It is a cheap device which uses a gas sensor with the Arduino. Its operation is featured in the video below and the raw circuit is also shown.

Along with the Arduino and gas sensor is the computer for reading values, a potentiometer or resistor of known value, a cable to hook the Arduino to the computer or to provide power, the Arduino kit, and the different sensors. An image of the sensor from Figaro is shown below.

In setting up the Arduino, it should be connected to the computer and be functional. To read the value from an analog input and display this on-screen, the Arduino will be programmed. Other alternative is to try just to wire up the potentiometer and read the value from it before adding the sensor.

An imgae of the circuit is shown below where the leads of the sensors are pointing towards the ground. In order to determine which pin is which, a small metal tab protruding from the sensor is made available. A breadboard can be used to make the connections without soldering. The connections will include sensor pin 1 to an outer pin of potentiometer and ground, sensor pin 2 to other outer pin of potentiometer, sensor pin 3 to Arduino +5V and sensor pin 4, and the middle pin of potentiometer to Arduino analog 0 input.

The Arduino will be connected to the computer when everything is connected. The reading of values will start after firing up the Arduino environment and hitting the ‘monitor serial input’ button in the Arduino software. The image below shows the device being used for testing. In the black space at the bottom of the Arduino program, the values can be seen scrolling. The numbers on the screen will be seen changing by blowing slowly for at least a few seconds over the top of the sensor.

The device is efficiently good in reading relative concentrations of chemicals without burning in the circuit for a week and adding a thermistor. This can really be useful although there are some nasties which cannot be detected.