Give the instrument industry a physical examinatio

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Before testing the air, give the instrument industry a physical examination

a batch of red formaldehyde detectors that do not meet the technical requirements have been brushed recently. The Shanghai market supervision department released the risk monitoring results of the formaldehyde detector for red products. The results showed that: no batch of formaldehyde detectors in the sampled samples met the technical requirements, and no batch of formaldehyde detectors in the set detection environment did not simply refer to technology. 6. Press the switch on the manual control box to the "on" position and the repeatability under the product innovation conditions met the requirements

coincidentally, AQSIQ organized the risk monitoring of indoor hazardous substance detector products in 2017, and randomly tested 30 batches of hand-held haze meters sold on e-commerce platforms, but none of the samples were qualified. The instructions of these products indicate that the detection accuracy of PM2.5 is high, and most of them can also detect formaldehyde, volatile organic compounds, etc

in recent years, with the public's in-depth understanding of the formaldehyde problem in indoor decoration and the health hazards of PM2.5, the requirement of testing followed. Therefore, formaldehyde and PM2.5 detectors, which are cheap and easy to carry, have appeared one after another and become a hot spot of sales. These instruments are generally only in size, and the public can easily obtain various data of indoor air quality

such a detector seems convenient, but it is actually very unreliable. Professionals found that these detectors basically use sensors. Due to the low price, poor quality of the sensor, the measurement accuracy is low. The technical route is also unreliable. The sensors basically adopt the diffusion sampling method. The detection results only reflect the instantaneous concentration of pollutants at a certain point, and cannot represent the concentration value of pollutants in the whole space. The local concentration of formaldehyde is affected by air flow rate, temperature, humidity, even the number of furniture, placement position and other factors, which leads to the measured value is unstable and the error rate is large. After disassembling the samples, it was also found that the design of the detector was relatively simple. Some products did not have auxiliary fans or other auxiliary air flow entry devices, and the inhaled air was less, so the accuracy of the detection could be imagined. In fact, air detectors need regular calibration services. These red detectors generally lack automatic calibration and self purification functions, and there is no follow-up tracking service of enterprises. Once the sensor is polluted by dust during use, its sensitivity will decline or even fail, which will mislead the public and even cause psychological panic

in the past, formaldehyde and PM2.5 detectors were expensive professional equipment. According to the accuracy requirements, the price ranged from tens of thousands to hundreds of thousands of yuan, which was owned only by a few professional departments and enterprises. In recent years, with the public's attention to outdoor and indoor air quality, similar detectors have gradually flown into the homes of ordinary people. At present, China does not stipulate that civil Portable detectors need to be certified by wear testing machines before they are listed. Civil formaldehyde detectors also lack unified technical standards. Many civil formaldehyde detectors are just a simple piece of electronic components. In the face of the new needs of the public today, the relevant departments should not only detect the civil formaldehyde in the market and inspect the extrusion pressure at the same time to ensure that the system pressure will not be too high, but also make up for the lost, formulate industry standards and technical specifications as soon as possible, and curb the current chaos of mixed people and uneven product quality in the industry; The public should not blindly pursue the so-called red products, and try to invite professional institutions to test the air quality with professional equipment

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