Here you will find the Pre-Purchase Frequently Asked Questions (FAQs) for Aeroqual’s Portable Air Quality Monitor.

1. What do I need to monitor air pollution with a portable monitor?

There are many different types of outdoor air pollution. Measuring them all would be too expensive, so regulators focus on a smaller group of common air pollutants, sometimes known as the criteria pollutants. The criteria pollutants are:

  • Nitrogen dioxide (NO2)
  • Sulfur dioxide (SO2)
  • Carbon monoxide (CO)
  • Ozone (O3)
  • Particulate matter (PM)

As always requirements should be confirmed with your local regulatory body.

2. What is a sensor head?

Sensors are housed within an interchangeable ‘sensor head’ that attaches to the monitor base. You can choose from up to 28 different gas and particulate sensor heads. Each sensor head contains a single gas or particle sensor. Swapping sensor heads takes seconds and no configuration or re-calibration is required.

Portable air quality monitor sensor options

3. How accurate is my sensor head? (re-word title to “how accurate are your sensor heads?”)

You can find our specifications for our sensor heads here:


Note: Accuracy may drift as the sensor ages.

4. How long do the sensor heads last?

Aeroqual recommends replacement after two years, however higher exposure levels or harsh environments can lead to a significant reduction in life expectancy. Your monitor display is likely to indicate Sensor Failure or Sensor Ageing if the sensor is nearing the end of its useful life.

Note: Sensor heads may degrade even when unused and in storage.

5. How many sensors can I use on the monitor at once?

You can only connect one gas or particulate sensor head at a time to monitor. However, you are able to connect the optional temperature and humidity sensor at the same time as a gas or particulate sensor head.

6. Can I use the PM sensor head with any portable monitor?

The PM sensor is compatible with Series 200/300/500 monitors with software version 6.4 introduced in November 2014.

7. What is the PPM to mg/m³ conversion factor?

PPM is an absolute measurement, whilst mg/m3 varies depending upon pressure and temperature. The portable monitor measures in PPM and applies a conversion factor if you wish to measure in mg/m3.

SensorPPM conversion to mg/m3

*as particulate matter varies in size, unlike a gas molecule, PPM is not a valid unit of measurement

8. Do I return the instrument for calibration?

Only the sensor head needs to be calibrated. The base unit does not need to be calibrated. All parameters are stored on the sensor head.

The sensor head calibration should be completed after the first year. Aeroqual does not recommend a second factory calibration, but rather replacement after two years of operation.

See a range of frequently asked questions on calibration here.

9. How long can I log data for (Series 500 only)?

The Series 500 handheld unit can store a limited number of data points (8188), meaning that the length of time that data can be logged depends upon the frequency and number of data points recorded. For example:

  • If you are logging every minute for one gas (i.e. one data point per minute) you can log for 8188 minutes.
  • If you are logging every minute for one gas, temperature and humidity (i.e. 3 data points per minute) you can log for 2729 minutes.

Decrease the logging frequency for the ability to log over a longer timeframe.

Note: Once capacity is reached new data will begin to overwrite the oldest logged data.

10. What communication options does the portable monitor have?

S200: None

S300: 0-5V Analog output (current reading only)

S500: 0-5V Analog output (current reading only), RS232 (current, logged data and instrument control) to PC software via USB adapter. RS232 protocol available upon request for third party software integration.

11. What is the “Control” function (Series 300 & 500 only)?

This is designed to control generation of a gas such as ozone from an ozone generator. The control pin can be wired to control a gas concentration between upper and lower concentration limits. The upper and lower limits can be set by the user via this control function.

Refer to the relevant section of the user guide for wiring instructions.

12. What accessories are available for the portable monitors?

Aeroqual offers a range of accessories to suit your application. See the range here.

13. Can I buy online?

Aeroqual does not sell online. If you have received a quotation from us and are ready to pay then you can pay by credit card online here.

If you want a quote then take a look at our product pages below, select the product you are interested in and request a quote.