Formaldehyde detection is a work that many owners will carry out, especially to control formaldehyde after the renovation of new houses, and it is necessary to determine the effect of governance. Only when the standards set by the state are met, the owners will be satisfied with the treatment effect, and then they can stay in their new houses with confidence. So what is the national standard for formaldehyde detection, and what is the detection value to be qualified?
What is the standard value of formaldehyde concentration?
At present, the national standards GB/T 18883-2002 and GB/T50325-2020 are used. The former standard stipulates that the standard concentration of formaldehyde is 0. 1 mg per cubic meter, while the latter standard is subdivided into two. They are aimed at a kind of civil construction projects (residential buildings, hospitals, old buildings, kindergartens, school classrooms and so on). ) and a class of civil buildings (office buildings, shops, hotels, cultural and entertainment venues, bookstores, libraries, gymnasiums, public transport waiting rooms, etc.). ), their standard values are slightly different. The formaldehyde concentration of a class of buildings cannot be higher than 0.07 mg per cubic meter, while the standard value of a class of buildings is. Therefore, it is necessary to judge the qualified concentration of formaldehyde according to different places and various restrictions.
What is a professional formaldehyde testing organization?
Professional formaldehyde testing identifies formaldehyde testing institutions with CMA qualification, because the methods and equipment used by such qualified institutions have been uniformly certified by the state, and the testing reports given by them are extremely authoritative and have legal effect. Whether it is a professional CMA testing laboratory or other testing institutions with CMA qualification, they all have strong professional ability and accurate professional testing technology, and can issue a complete testing report in a very short time for the direct reference of the majority of owners. The difference is that the test results are more accurate and the fees are higher.
What is the method of detecting formaldehyde?
Professional methods for detecting formaldehyde mainly include spectrophotometry and meteorological chromatography, and their detection principles are as follows:
Spectrophotometry is a method for qualitative and quantitative analysis by measuring the absorbance or luminous intensity of light at a specific wavelength or within a certain wavelength range. Indoor formaldehyde content is determined by sophisticated testing instruments and some potions. The principle of gas chromatography is that formaldehyde in the air is adsorbed on the carrier coated with 2,4-dinitrophenylhydrazine (2,4-dnph) 6201under acidic conditions to generate stable formaldehyde hydrazone. After elution with carbon disulfide, it was separated by 0 V chromatographic column and determined by hydrogen flame ionization detector. Retention time is used for qualitative analysis and peak height is used for quantitative analysis.
The only thing we need to see is whether the report is credible. If it is credible, it depends on the concentration of formaldehyde detection. As long as it is strictly lower than or equal to the national standard concentration, you can choose to stay, even if it exceeds the standard.