What do the colors mean on the AirCasting app?

January 14, 2022

Frequently Asked Questions

General Topics
Data Collection
AirCasting App and Kids Making Sense Mapping Website
Other Air Quality and Air Sensor Topics

General Topics

Why did we switch to the AQ-go sensor?

We want students to be able to understand how air sensors work, from the big picture functions down to the components inside the sensor. The clear casing of the AQ-go enables students to easily see the parts inside of the sensor and understand the engineering behind it.

Both the AQ-go and the AirBeam measure three sizes of particulate matter (PM) – PM₁ (PM<1 micrometer in diameter), PM_2.5 (PM<2.5 micrometers in diameter), and PM₁₀ (PM<10 micrometers in diameter). Both sensors also measure the temperature and relative humidity of the air that is inside the sensor. They also use the same components inside each sensor.

How do the AirBeam/AQ-go sensors work?

The AirBeam/AQ-go uses a light-scattering technique to detect PM in the air. A fan inside the AirBeam/AQ-go pulls air in and a laser light shines on the air. PM in the air scatters the laser light and the AirBeam/AQ-go measures the light scattered by the PM, then uses math to calculate the number and size of the PM. The data is then sent to the AirCasting app.

You can read more about how the AirBeam works at the Habitat Map website: https://www.habitatmap.org/blog/AirBeam-technical-specifications-operation-performance

What do the AirBeam/AQ-go measure?

The AirBeam/AQ-go measures 3 categories of particle matter: PM₁ (PM<1 micrometer), PM₅ (PM<2.5 micrometers in diameter), and PM₁₀ (PM<10 micrometers in diameter).
The AirBeam/AQ-go measures the temperature and relative humidity of the air inside the sensor. These values do not reflect the outdoor temperature and relative humidity.

How can I get started with using the AirBeam/AQ-go?

To help you get started, the Kids Making Sense curriculum includes a Quick Start Guide, which explains how to use the AirBeam/AQ-go sensor and AirCasting App. You can also look at the free resources section of our website for activity ideas.

What is the AirBeam/AQ-go unable to measure?

As with all technology, the AirBeam/AQ-go does have some limitations:

The AirBeam/AQ-go does not measure gases like ozone or nitrogen dioxide.
The AirBeam/AQ-go does not measure outdoor temperature or relative humidity. The temperature and relative humidity sensors in the sensor measure the internal conditions of the AirBeam/AQ-go. These measurements do not reflect the external temperature and relative humidity.
Currently, AirCasting, the AirBeam/AQ-go data viewing app, only works on the Android operating system, and does not work on the iOS operating system (e.g., iPhone, iPad).
According to evaluations by experts, the AirBeam/AQ-go does not accurately measure the PM₁₀ size category. You can read more about the comparison of the AirBeam to regulatory measurements here: http://www.aqmd.gov/aq-spec/sensordetail/habitatmap-AirBeam.

The lights on the AirBeam/AQ-go have gone off. Is there a problem? Is the sensor on?

The lights on the base of the AirBeam/AQ-go turn off after about 1 minute to prolong battery life, but the unit continues to run. If you are unsure if the AirBeam/AQ-go is on, listen for a fan. If you can hear the fan, this means it is still functioning.

How do I know if the sensor is working?

You can check the sensor’s operation by viewing the data in real time on the AirCasting app. As you watch the PM levels, try doing something that might generate some dust (like hitting an upholstered chair or blowing dust off a bookshelf), and watch to see if the PM levels increase.

What is the lifetime of the AirBeam/AQ-go?

An AirBeam/AQ-go has a lifetime of three to five years.

How long does a single charge last for the AirBeam/AQ-go?

The AirBeam/AQ-go will run for 10 hours when fully charged.

Is the sensor waterproof/weatherproof? How can I protect the sensor during bad weather?

The AirBeam/AQ-go is weather-resistant but not weatherproof. The AirBeam/AQ-go should be protected from extreme heat, cold, and rain. If it is raining outside, use an umbrella to protect the AirBeam/AQ-go.

Can I leave the sensor outside to measure PM in one location for an extended period of time?

You can use the AirBeam/AQ-go and phone to measure in one location over time as long as it is protected from direct sun, rain, and extreme weather. Keep in mind that the connected phone will need to be next to the AirBeam/AQ-go during data collection.

Data Collection

How can I use AirBeam/AQ-go data?

Data collected with the AirBeam/AQ-go as part of the Kids Making Sense program can be used for education and increasing air quality awareness.

Can anyone use or look at the data we collected with the AirBeam/AQ-go?

Yes, once data is collected it is made available to anyone who visits the Kids Making Sense mapping website. This is also true for any notes you made on the app during data collection.

Should I expect the AirBeam/AQ-go to read zero?

Even in clean air, the AirBeam/AQ-go might not read zero, and may read a very low number instead. Even when the air is very clean, we often generate PM from normal activities. For example, the simple act of walking can kick up dust or cause particles to fall off our clothing.

If the AirBeam/AQ-go constantly reads 0 no matter the environment, there is likely a problem with the detector inside the AirBeam/AQ-go. If the PM channels, temperature, and relative humidity all read 0, there is a problem with the detector inside the AirBeam/AQ-go.

If I measure a high PM level, what should I do?

Measuring a high PM level may or may not be a cause for concern. If you measure a high PM level, make a note that includes when and where the measurement was taken, how long it lasted, and what you observed in the area at the time. High readings over a short duration may not be real, or may be caused by something that occurred close by, such as someone smoking a cigarette or kicking up dust. Levels that are elevated for longer periods of time may be more concerning. In these cases, think about steps you can take to bring the readings down, like moving to a different area or increasing ventilation if you are indoors.

Why don’t the values match on the two sensors that I have?

Sometimes two sensors measuring in the same place at the same time don’t give the exact same readings. There are a number of possible reasons for this:

It could be due to something you are doing, for example covering the air inlet or exhaust on the sensor.
One sensor might be dirty or damaged.
The sensors may have been built slightly differently.

It’s a good idea to operate the sensors together for a while to learn how the readings compare before separating them to measure in two different places.

I’m trying to compare my AirBeam/AQ-go readings to another type of air sensor that measures PM. Why don’t their readings match?

It is not uncommon for two different types of sensors to give you different readings. Here are some possible reasons for different readings.

The difference could be due to something you are doing, such as covering the air inlet or exhaust on one of the sensors.
One of the sensors might be dirty or damaged.
The type of technology used in each sensor may be different.
The sensors may be placed inside the protective housing differently.
Different sensor manufacturers may analyze data differently before sharing it with users.

Regardless of whether you have two AirBeam/AQ-go sensors, or one Airbeam/AQ-go and one sensor from another manufacturer, it is always a good idea to operate the sensors together for a while to learn how the readings compare before deploying them separately.

Why are the temperature measurements from the sensor different than the temperature in my weather app?

The temperature and relative humidity sensors are inside the AirBeam/AQ-go, and reflect the operating temperature and relative humidity of the air inside the sensor. These measurements do not reflect the temperature and relative humidity outdoors.

AirCasting App and Kids Making Sense Mapping Website

What can I learn from the Kids Making Sense mapping website?

You can see a map of PM data collected from all Kids Making Sense AirBeam/AQ-go users on the Kids Making Sense mapping website. You can learn about air quality near you or in other parts of the U.S.

Do I need Wi-Fi to use the AirBeam/AQ-go and AirCasting app?

Yes, you will need Wi-Fi (1) when you create and log in to an AirCasting Profile on a paired Android phone before starting an AirCasting session, (2) to load the map in the AirCasting app as you’re starting a session, and (3) to upload and view data on the Kids Making Sense mapping website after you’ve finished a session.

Wi-Fi is not needed during data collection, because the AirBeam/AQ-go and AirCasting app communicate with each other via Bluetooth.

Do I have to use the Android phone that came with the AirBeam/AQ-go?

No, you do not have to use the Android phone that came with the AirBeam/AQ-go. Since the Android phones provided with the Kids Making Set kit have been paired with the AirBeam/AQ-go units though, you will need to reference the “How to pair a phone with the sensor help guide” for instructions if you decide to use your own Android phone instead. We do recommend that you use the Android Phone that comes with the AirBeam/AQ-go sensor since it is already paired and doesn’t have other apps installed.

I can’t find my AirCasting session on the Kids Making Sense mapping website (maps.kidsmakingsense.org).

Make sure the Android phone is connected to Wi-Fi. Depending on the strength of your Wi-Fi connection, the AirCasting session may take a few minutes to upload.
On the AirCasting mapping website, use your AirCasting profile name, session tags, and date information to search for your AirCasting session.
If you are still not seeing your AirCasting session on the AirCasting map, you may need to force the session to upload by following these instructions:
- Open the AirCasting app on your phone and press Mobile dormant. Your latest session should be listed at the top of the page.
- Press on this section and drag your finger down on the screen. If done correctly, this will cause a rotating circle to appear. This means the app is syncing with the Kids Making Sense map. Uploading a session may take up to 20 minutes depending on your Wi-Fi strength.
Finally, if none of the steps listed above work, double-check that the backend settings in the AirCasting app are set correctly by following these steps:
- Open the AirCasting App.
- Select the three dashes at the top right and select Settings.
- Select Backend Settings. For the Backend Address, enter kidsmakingsense.org Leave the Backend Port at 80.

This error pops up when I open the map in the AirCasting app: “Without a GPS fix you can’t map your session or contribute it to the CrowdMap.”

This error occurs when your phone cannot get a strong GPS signal indoors. While connected to Wi-Fi, try stepping outside or getting closer to a window to make it easier for the phone to get a GPS signal.

Can all air pollutants be measured with a hand-held air sensors?

No, not all air pollutants can be measured using a hand-held air sensor. A more expensive piece of equipment is needed to measure certain pollutants, or sometimes a sample needs to be taken to a laboratory for analysis. If you want to learn more, contact to a local air quality agency, a U.S. Environmental Protection Agency (EPA) Regional office, an air quality professional, or a university scientist to ask questions.

What kinds of sources generate PM?

A number of sources indoors and outdoors can generate PM. Refer to the activities in your Kids Making Sense workbook for more information about sources.

Where can I learn more about the health impacts of air pollution?

You can read more about the health and environmental effects from air pollution by visiting any of the following links:

The Health Effects of Air Pollution Brochure – aqmd.gov/docs/default-source/publications/brochures/the-health-effects-of-air-pollution-brochure.pdf

Dirty Air: The Health Effects of Air Pollution – https://www.aqmd.gov/docs/default-source/students/download-the-whole-brochure.pdf?sfvrsn=0