<blockquote>
  <p>Ambient or roadside concentrations for each pollutant, over different
  averaging times, will be converted into an index value. <strong>In general,
  there are <a href="https://docsbay.net/a-study-of-the-air-pollution-index-reporting-system" rel="nofollow noreferrer">three common methods</a> to achieve this.</strong> The most popular
  approach is often called the <strong>US-based system</strong>. Pollutant
  concentrations for each pollutant are transformed onto a normalised
  numerical scale of 0 to 500, with an index value of 100 corresponding
  to the primary National Ambient Air Quality Standard (NAAQS) for each
  pollutant (USEPA, 2006, website 14). Places like Singapore, China,
  Thailand, Malaysia, South Korea, Taiwan, Hong Kong, and Macau designed
  their AQI /API systems based on the US model. The key reference point
  of these systems would be the index value of 100, which is based on
  the short-term air quality standards of the respective jurisdictions.
  Very often, the index value of 50 is anchored to the long-term air
  quality standards.</p>
  
  <p>A similar approach is being used in Australia, whereby <strong>pollutant
  concentrations are also being transformed onto a scale.</strong> There,
  however, a linear or proportional scale is used instead of a
  normalised scale (i.e. a scale which takes the variation into
  account), and the index is then calculated in direct proportion to the
  air quality standards or environmental goals (Ove Arup, 2007, 1).
  Moreover, the scale used in New South Wales is different from the one
  used in Queensland, Victoria, and Adelaide (in South Australia). In
  New South Wales, an index value of 50 means that the pollutant
  concentration is equal to the standard level. For the other states and
  cities, the index value of 100 carries the same meaning (Ove Arup,
  2007, 1; website 4).</p>
  
  <p>The third approach is the <strong>banding system</strong>, which is more popular in
  European countries like the UK and France (websites 3, 13). The main
  deviation is that instead of using an index scale of 0 to 500, a scale
  of 0 to 10 is being used. For the UK system, this index scale of 10 is
  further broken down into four bands of ‘low’ (1-3), ‘moderate’ (4-6),
  ‘high’ (7-9) and ‘very high’ (10) (website 13). The key reference
  point for this banding system is the breakpoint value between the
  ‘low’ and ‘moderate’ bands. The lower bound of index value 4 is set to
  correspond to the UK Air Quality Standards for all pollutants but NO 3
  2. In this case, the 1-hour national standard for NO2 is 200 g/m , whereas the lower bound of index value 4 for NO2 is 287 g/m3 (website
  13).</p>
</blockquote>

<p><a href="https://docsbay.net/a-study-of-the-air-pollution-index-reporting-system" rel="nofollow noreferrer">A Study of the Air Pollution Index Reporting System</a> by <em>Prof. Wong Tze Wai</em>
School of Public Health and Primary Care The Chinese University of Hong Kong </p>

CC BY-SA 4.0
2019-07-10T01:50:32.527Z
2019-07-10T01:50:32.527Z
PeterStricker
<p>The AQI calculation does not require that all pollutants be measured.  Instead, it uses the pollutants that are available and then uses a function (chosen by the overarching regulatory agency) that equates health risk categories to the pollutant concentrations.  The pollutant with the highest health risk (at present concentrations) will effectively determine the corresponding AQI.  See here for <a href="https://en.wikipedia.org/wiki/Air_quality_index#United_States" rel="noreferrer">how the USA EPA computes their AQI</a>.</p>

<p>In order to detect the most commonly monitored pollutants, you would need an ozone analyzer and a PM2.5 monitor.  This is quite expensive.  A good single-pollutant monitor will cost thousands of dollars to purchase and many continuing costs.  You will also need calibration equipment and standards.  Depending on what AQI network you will be using as a reference, the model of instrument that you use will have to meet certain specifications in order for the data to be valid.  <a href="http://www.teledyne-api.com/" rel="noreferrer">Teledyne</a> is an example of a company that makes equipment that would meet the qualifications for the USA AirNOW network.  You may also find of interest their nice <a href="https://www.airnow.gov/index.cfm/images/index.cfm?action=airnow.calculator" rel="noreferrer">AQI calculator</a>.</p>

CC BY-SA 3.0
2016-12-27T16:18:47.337Z
Thanks, but the I wanted to know about the technology like sensors and stuff. Not the info on calculating AQI or existing products.
iamgr007
CC BY-SA 3.0
2016-12-27T16:51:26.233Z
I think you are missing the point.  Sensors don't measure the AQI.
f.thorpe
CC BY-SA 3.0
2016-12-27T16:59:55.470Z
I know how to calculate the AQI, I mentioned that in the question. I need the data from the air which can be measured by sensors which in turn are used to calculate the AQI. Am I clear?
iamgr007
CC BY-SA 3.0
2016-12-27T17:19:30.030Z
Yes I saw you edited your question.  Did you look at the Teledyne link in the answer?
f.thorpe
CC BY-SA 3.0
2016-12-27T17:27:23.643Z
ok,I don't want to be rude but what good does that link do for me? I'm not looking for products to buy, I want to make my own device. Also, I didn't edit my question for that. It'll be good if you delete your answer because it is completely pointless.
iamgr007
CC BY-SA 3.0
2016-12-27T17:32:20.730Z
Perhaps you should research what type of sensor (that actually exists) you would like to make.  Then you could form a question that is answerable to your liking.
f.thorpe
CC BY-SA 3.0
2016-12-27T17:32:39.953Z
Let us [continue this discussion in chat](http://chat.stackexchange.com/rooms/50785/discussion-between-caffeinator13-and-farrenthorpe).
iamgr007
CC BY-SA 3.0
2016-12-27T15:28:51.940Z
2016-12-27T15:28:51.940Z
f.thorpe
<p>I'm unable to find good sources to make myself an <code>AQI(Air quality Index)</code> measuring device. All I was able to find was the way it is calculated in different regions. But I need some help with the technology used to measure the concentrations of different pollutants like <code>SO2, NOx, PM10, PM2.5, etc.</code>  </p>

<p>Are there any good papers or patents on the technology used to measure the AQI?</p>

<p>Any help is appreciated. Thanks.</p>

<air-pollution><pollution><air-quality><technology><pm2.5>
How can I test the Air Quality?
iamgr007
# How can I test the Air Quality?

(Asked by: username_0 on 2016-12-27)

I'm unable to find good sources to make myself an `AQI(Air quality Index)` measuring device. All I was able to find was the way it is calculated in different regions. But I need some help with the technology used to measure the concentrations of different pollutants like `SO2, NOx, PM10, PM2.5, etc.`

Are there any good papers or patents on the technology used to measure the AQI?

Any help is appreciated. Thanks.

**Tags:** air-pollution, pollution, air-quality, technology, pm2.5


---

## 2 answers

### Answer by username_2 on 2016-12-27. Score: 5 | Accepted answer

The AQI calculation does not require that all pollutants be measured. Instead, it uses the pollutants that are available and then uses a function (chosen by the overarching regulatory agency) that equates health risk categories to the pollutant concentrations. The pollutant with the highest health risk (at present concentrations) will effectively determine the corresponding AQI. See here for [how the USA EPA computes their AQI](https://en.wikipedia.org/wiki/Air_quality_index#United_States).

In order to detect the most commonly monitored pollutants, you would need an ozone analyzer and a PM2.5 monitor. This is quite expensive. A good single-pollutant monitor will cost thousands of dollars to purchase and many continuing costs. You will also need calibration equipment and standards. Depending on what AQI network you will be using as a reference, the model of instrument that you use will have to meet certain specifications in order for the data to be valid. [Teledyne](http://www.teledyne-api.com/) is an example of a company that makes equipment that would meet the qualifications for the USA AirNOW network. You may also find of interest their nice [AQI calculator](https://www.airnow.gov/index.cfm/images/index.cfm?action=airnow.calculator).

> **Comments:**
> **username_0**: Thanks, but the I wanted to know about the technology like sensors and stuff. Not the info on calculating AQI or existing products.  
> **username_2**: I think you are missing the point.  Sensors don't measure the AQI.  
> **username_0**: I know how to calculate the AQI, I mentioned that in the question. I need the data from the air which can be measured by sensors which in turn are used to calculate the AQI. Am I clear?  
> **username_2**: Yes I saw you edited your question.  Did you look at the Teledyne link in the answer?  
> **username_0**: ok,I don't want to be rude but what good does that link do for me? I'm not looking for products to buy, I want to make my own device. Also, I didn't edit my question for that. It'll be good if you delete your answer because it is completely pointless.  
> **username_2**: Perhaps you should research what type of sensor (that actually exists) you would like to make.  Then you could form a question that is answerable to your liking.  
> **username_0**: Let us [continue this discussion in chat](http://chat.stackexchange.com/rooms/50785/discussion-between-caffeinator13-and-farrenthorpe).  

---

### Answer by username_1 on 2019-07-10. Score: 1

> Ambient or roadside concentrations for each pollutant, over different
> averaging times, will be converted into an index value. **In general,
> there are [three common methods](https://docsbay.net/a-study-of-the-air-pollution-index-reporting-system) to achieve this.** The most popular
> approach is often called the **US-based system**. Pollutant
> concentrations for each pollutant are transformed onto a normalised
> numerical scale of 0 to 500, with an index value of 100 corresponding
> to the primary National Ambient Air Quality Standard (NAAQS) for each
> pollutant (USEPA, 2006, website 14). Places like Singapore, China,
> Thailand, Malaysia, South Korea, Taiwan, Hong Kong, and Macau designed
> their AQI /API systems based on the US model. The key reference point
> of these systems would be the index value of 100, which is based on
> the short-term air quality standards of the respective jurisdictions.
> Very often, the index value of 50 is anchored to the long-term air
> quality standards.
>
> A similar approach is being used in Australia, whereby **pollutant
> concentrations are also being transformed onto a scale.** There,
> however, a linear or proportional scale is used instead of a
> normalised scale (i.e. a scale which takes the variation into
> account), and the index is then calculated in direct proportion to the
> air quality standards or environmental goals (Ove Arup, 2007, 1).
> Moreover, the scale used in New South Wales is different from the one
> used in Queensland, Victoria, and Adelaide (in South Australia). In
> New South Wales, an index value of 50 means that the pollutant
> concentration is equal to the standard level. For the other states and
> cities, the index value of 100 carries the same meaning (Ove Arup,
> 2007, 1; website 4).
>
> The third approach is the **banding system**, which is more popular in
> European countries like the UK and France (websites 3, 13). The main
> deviation is that instead of using an index scale of 0 to 500, a scale
> of 0 to 10 is being used. For the UK system, this index scale of 10 is
> further broken down into four bands of ‘low’ (1-3), ‘moderate’ (4-6),
> ‘high’ (7-9) and ‘very high’ (10) (website 13). The key reference
> point for this banding system is the breakpoint value between the
> ‘low’ and ‘moderate’ bands. The lower bound of index value 4 is set to
> correspond to the UK Air Quality Standards for all pollutants but NO 3
> 2. In this case, the 1-hour national standard for NO2 is 200 g/m , whereas the lower bound of index value 4 for NO2 is 287 g/m3 (website
> 13).

[A Study of the Air Pollution Index Reporting System](https://docsbay.net/a-study-of-the-air-pollution-index-reporting-system) by *Prof. Wong Tze Wai*
School of Public Health and Primary Care The Chinese University of Hong Kong


---

