Experts frankly say: Cheap air pollution detectors have limited use

(Reporter Zhou Chen, intern reporter Lin Yuxuan) People are paying more and more attention to air pollution, which promotes the prosperity of the air pollution detector market
.

In recent years, when the smog is severe, some e-commerce air pollution detectors have even sold out

However, are these air pollution detectors used by civilians really accurate? On July 7, 2016, two atmospheric chemists Alastair Lewis and Peter Edwards from the National Center for Atmospheric Sciences, University of York, UK, wrote an article in Nature, questioning cheap air pollution The accuracy of the detection device calls on researchers and the government to strengthen the inspection of the accuracy of these detectors and issue relevant standards
.

Caixin reporter interviewed Peter Edwards, one of the authors, on this issue.
He introduced to Caixin reporter that the technologies used in traditional air pollution detection devices have been repeatedly tested by professional organizations before they are used.
The methods are all traceable, and the uncertainty is also controllable
.

The only problem with these devices is their high cost.

Although the cheap and small detector mentioned in the above article is low in price and claimed to be accurate, the technology used has not been rigorously tested and cannot be accurately measured in a real atmospheric environment
.

In a small number of studies, these cheap devices were compared with professional devices to detect specific air pollutants.

Caixin reporter: In what fields are these cheap detectors generally used?

Peter Edwards: The cheap detectors mentioned in the article are sold by various companies.
Some are used for city-wide air quality testing, and some are used for air monitoring around individuals
.

Most of the technologies used by these detectors have been used for industrial risk detection in the past.

　　Caixin Reporter: For users, do they just use these data as a reference, so is it really important to have standards?

　　Peter Edwards: If cheap detectors are only used as a rough estimate of air pollution, then whether they can provide accurate and reliable data is really not that important
.

But under such circumstances, these detectors should be sold and marketed to explain their limitations, and anyone who purchases these instruments should be informed of these conditions

　　Caixin reporter: What is the difference between an official high-quality tester and a cheap tester for personal use?

　　Peter Edwards: The technology used in professional testing equipment has been developed for decades to measure specific pollutants in the real atmospheric environment
.

These devices are highly specialized instruments based on spectroscopy or mass spectrometry, which can minimize interference from other chemical components to maximize their accuracy and reliability

　　On the contrary, the technologies used by most cheap detectors were not invented to detect the chemical composition in the atmospheric environment.
They were originally used for industrial purposes.
In industrial application scenarios, the target gas concentration is much higher than that of the general environment.
, And the interference will be much less
.

How these technologies work in the real atmospheric environment has yet to be verified

　　Caixin reporter: Why is the cost gap between professional equipment and cheap equipment so large?

　　Peter Edwards: The components required for professional equipment are often very expensive, such as lasers and highly reflective mirrors
.

In addition, testing and verification of equipment performance will also increase costs

　　Caixin reporter: Is the accuracy of the detector proportional to its cost?

　　Peter Edwards: Basically, but it's not just a question of price
.
Someone might sell an instrument with very low accuracy at a very high price
.
The most important thing for an instrument is whether the technology it uses is consistent with its purpose
.