1, formaldehyde test paper detection: it is very cheap, but it only imitates the color development principle in GB/T 18204.2 phenol reagent spectrophotometry. Because formaldehyde in the air is not collected quantitatively, it is impossible to calculate the mg/m of formaldehyde content unit. In addition, the numerical error is too large by visual inspection with naked eyes.
2, portable formaldehyde detector detection: it is difficult to distinguish between true and false. Taobao's portable formaldehyde detector with tens of yuan and hundreds of yuan is almost deceptive, which does not conform to any detection principle. It does not need to change test paper, collect quantitative formaldehyde in the air, and recycle it indefinitely. It is absolutely impossible to achieve. However, there are also some better portable formaldehyde detectors, at least 5000 yuan, generally using test paper photoelectric spectrophotometry. Every time/point/room exam, you need to change the test paper (the price of the test paper is about one in 50 yuan). When testing, the formaldehyde in the gas will be collected at a constant speed for 30 minutes, and then analyzed, which is more in line with the principle and can be rented. The total cost is probably: examination paper fee (about one room in 50 yuan)+freight.
3. Formaldehyde testing of in addition to formaldehyde companies: It is not excluded that many in addition to formaldehyde companies have strong formaldehyde control level and fair testing. However, most companies in in addition to formaldehyde have the problem that it is difficult to distinguish between professions fairly. The first is fairness. If all the tests before in addition to formaldehyde, the service in in addition to formaldehyde and the acceptance test after in addition to formaldehyde are handed over to in addition to formaldehyde, it is really unfair to be a referee and an athlete. After spending thousands of dollars in in addition to formaldehyde, do you wonder whether the test before in addition to formaldehyde exceeded the standard or whether the acceptance test after in addition to formaldehyde reached the standard? The other is professionalism. Many companies in in addition to formaldehyde have joined in, and the service in in addition to formaldehyde should be ok. However, in formaldehyde detection, the detection instrument is simple (the spectrum is not up to standard), the detection standard is unknown (whether it is GB/T 18883 closed 12 hour or GB50325 closed 1 hour, almost unclear), the process is chaotic and the conditions are not strict. It can also detect that formaldehyde exceeds the standard, which is nonsense. The boiling point of formaldehyde is 19℃, less than 19℃. Volatilization is extremely slow and hardly exceeds the standard. When the temperature is higher than 19℃, the volatilization will be accelerated, and the volatilization will increase by about 12% with each increase of 1℃. In winter, formaldehyde should be detected at least above 20 degrees, and it is generally recommended to turn on the air conditioner to 25 degrees).
4. Small third-party testing institutions that only do testing: These institutions are generally composed of university laboratories, small testing companies and social semi-public testing institutions. Because there is only testing, there is no governance, the testing results are fair, the testing equipment is relatively better, and the professional knowledge is relatively stronger. The price is generally about one or two hundred yuan per room, which is more in line with the needs of ordinary families.
5. Third-party testing company with CMA testing qualification: The testing company recognized and awarded CMA testing qualification by the Government Bureau of Metrology is very fair and professional, and the testing report stamped with CMA issued by it has legal effect and can be directly used in litigation. It is suitable for kindergartens, schools, hospitals, commercial disputes and other occasions to check the price of a room around 500 yuan. Of course, parents with strong sense of responsibility and local families can also choose.