Air Quality Extender Kit

The Air Quality Sensor Extender for the OurWeather Weather Kit has a total of six parts.

• Grove I2C Air Quality Sensor
• Grove I2C High Resolution Analog to Digital Converter
• Grove I2C Hub
• Grove Cables (3)
• Raspberry Pi, Arduino and ESP8266 Software Provided

The Air Quality Sensor Extender Kit can be used in the OurWeather Kit as well as in stand alone Raspberry Pis, Arduino and ESP8266 systems.

How does this Kit work?

The Air Quality Extender Kit works by measuring a wide scope of harmful gases such as carbon monixide, alcohol, acetone, thinner, formaldehyde and so on as well as being sensitive to particulate count. Due to the method used to measure the contaminants, this Air Quality sensor can not output specific data to describe target gases' concentrations quantitatively. But it's still good enough to be used to describe qualitative air quality.

IMG_1149The Air Quality sensor requires a warm up time of about 2 minutes after power on before it will be reporting good data.

The Air Quality sensor is based on a Winsen MP503 Air-Quality Gas Sensor. The complete specification for the MP503 is on the Air Quality Sensor Extender Kit product page on www.switchdoc.com.

This sensor is designed for indoor use but can be used outdoors if it is covered and protected from high humidity.

Do not use any silicon based spray or lubricant products around the Air Quality sensor. Use of those products will rapidly reduce the sensitivity of the sensor.

This unit requires relativity clean air conditions when starting up.

When testing the sensor by using the cardboard box and hair spray test setup, do not spray the hairspray directly on the sensor. Spray it in the air around the sensor. It does not take much hairspray!

The analog voltage from the Air Quality sensor is converted by the SwitchDoc Labs Analog to Digital Converter into a 16 bit value that is read by Our Weather and converted into a qualitative gauge of the air quality. See these values below.

What Does the Air Quality Sensor Report?

The AirQuailty sensor reports a single analog voltage describing the overall air quality. We take this analog value and convert it to a digital reading (from 0 to about 65000). The OurWeather software then interprets this number and reports the qualitative air quality.

Following is digital reading and the qualitative interpretation:

If you would like to read the sensor value directly, and you have an OurWeather kit, type the following into your browser:

http:///AirQualitySensor where is the IP number of your OurWeather unit. For example, if your IP address of the OurWeather unit (viewable when the OurWeather Unit boots up - See OurWeather Assembly and Operations manual) is 192.168.1.141, then you would type:

http://192.168.1.141/AirQualitySensor

and OurWeather returns the following to your browser:

{"AirQualitySensor": 3416, "id": "1", "name": "OurWeather", "connected": true} The value of the AirQualitySensor is 3416, which means there is some gas and particulates in the air, or Low Pollution.