Compact air quality sensors: Should you perform co-location corrections?

The key promise of compact air quality sensors is to measure air pollution at low cost. However, low maintenance costs and easy usability often come with trade-offs in measurement accuracy. Here is a look at what types of sensors require co-location corrections, and what sets the Vaisala Air Quality Transmitter AQT560 apart.

Co-location with traditional air quality sensors

Traditional particle sensors have required co-location corrections for accurate particle measurements primarily because they measure particles indirectly; the mass of particles is estimated based on their optical properties. Mass calculations are affected by humidity, temperature, and particle types. Local conditions are accounted for by comparing the compact sensor to reference-grade measurements on-site. The sensor’s output is then corrected using offset adjustments.

Co-location corrections have significant drawbacks. They are difficult and time-consuming to arrange, and reference-grade sensors require expertise and are generally operated by government agencies. For co-location correction to be effective, the comparison period should be as long as possible—at least several weeks. Even after the correction is applied, seasonal or location changes may still have large effects and significantly reduce its effectiveness.

Advanced technology in AQT560

AQT560 is also an optical sensor but works on a different principle. Vaisala’s proprietary LPC technology generates a thin laser sheet, enabling the detection of each particle. This method is much less affected by local conditions, and the size of the particle is measured accurately. Combined with robust production calibration, AQT560 measures accurately straight out of the box, eliminating the need for costly corrections.

AQT560 also includes reference-grade temperature and humidity sensors that do not saturate and are well-ventilated, ensuring accuracy in all conditions and reliable all-weather performance. The algorithms that calculate the particulate matter (PM) or gas concentration values are all incorporated within the sensor itself, with no need for data modification or cloud processing. In other words, you can trust the sensor's output as it is.

Learn more about AQT560 and how it can help you see the air like never before.