The idea of having an Air Quality Monitor anywhere you go seems good especially when you can have 9 sensors with you. So here is a tip on how to convert a stationary IoT indoor AQ monitor to a portable one, in this case I will demonstrate it with the uHoo because I really want to measure some NO2 and O3 concentrations in some busy spots of the city.

There two ways to do that, one of which isn’t easy but bear with me.

Method 1 (easy)

For the first method which is the easiest, I am going to set up my phone with the same SSID and Password as my home WiFi router and the same credential I have previously set my uHoo device up. My home WiFi broadcasts a signal with the name SSID: myHome_WiFi and the Password: 12345678. So I need to set my phone up with the same information.
On an iPhone with a 3G/4G internet connection go to Setting–>General–>About–>Name and change it to myHome_WiFi. For the password go to Setting–>Personal HotSpot–>Wi-Fi Password and change it to 12345678.
On an Android phone is a bit easier because there is dedicated menu inside the Setting for the Personal Hotspot where everything is together, but I don’t have any Android device to demonstrate it.
Finally, turn on the Personal Hotspot and then connect the uHoo device to the USB power bank of your choice, I use a 10,000mah lithium battery. (Make sure your home WiFi is off or out of reach). Wait 2 minutes and launch the uHoo app. Done!

Method 2 (difficult)

For the second method in case you don’t want to change your phone name and password or you don’t want the rest of your house WiFi electronic devices to connect to your phone then you have to hardware reset uHoo and establish a new WiFi connection from scratch from the uHoo app. This method requires two phones or one phone and one tablet (uHoo has an iPad app) in order to create the personal hotspot from your phone and follow the instructions the uHoo app provides on the other device (phone or tablet) on how to reset it and connect it to the new WiFi network.

Experience

Setting up the device in order to use it as a portable AQM with the help of a power bank and your 3G/4G internet connection of your phone isn’t a piece of cake but with the instructions above you can achieve it. Remember the device isn’t designed to work as an outdoor monitor but as long as we use our brains a little bit more we can achieve a lot of cool stuff.

For the initial testing I took the device to a public park/garden here in my city and there is a busy road near this park. It was a super bright and sunny day and it is interesting to see how the Ozone O3 sensor responded when I moved from the park to the road at 18:50. Remember: NO2+VOC+SUN=O3. We can see the same peaks at the VOC sensor and the PM2.5 sensor. Have in mind that some of the sensors need some time to become available like the VOC.

Some environmental experts discourage people from measuring the Air Quality with low-cost devices because the sensors are unable to give as accurate measurements as the official AQ stations which worth thousands of dollars. However, I am in favor of this tactic, I believe people must take actions and a low-cost device is what will allow them to see the air. Although these sensors can’t be compared with the ones in the official AQ stations, they are able to give a trend of the air quality and help people recognize the problem.