First of all, it is clear that the ambient air VOC monitoring equipment discussed below refers to instruments used for continuous automatic on-line monitoring of VOC components in ambient air, including at least 57 PAMS ozone precursors. Such instruments are deployed in cities to identify VOC species that contribute significantly to ozone production by monitoring the VOC fraction, and then reduce these species to achieve the goal of reducing urban ozone concentrations to solve the ozone pollution problem.
Environmental air VOC monitoring equipment is broadly divided into gas chromatography principle (GC-FID) and gas chromatography-mass spectrometry principle (GC-MS). GC-FID principle of the instrument can only detect 57 kinds of PAMS, but can not monitor the oxygen-containing VOC, i.e., reactive aldehydes and ketones VOC, and can not monitor the TO-15 type of VOC, if you want to measure the above two types of VOC can only be measured with the GC-MS principle instrument. GC-MS principle instrument.
At present, there are many manufacturers of VOC automatic on-line equipment for ambient air in China. Reference can be made to the "ambient air volatile organic compounds gas chromatography continuous monitoring system certification testing qualified product list (as of March 31, 2020)" web link issued by the China Environmental Monitoring General Bureau
But in addition to the list there are also many domestic manufacturers of the instrument is used in large quantities at all levels of the environmental agencies, I personally believe that it is not only on the list of manufacturers to be reliable. China in 2018-2019 introduced the relevant standards (HJ1010-2018 ambient air volatile organic compounds gas chromatography continuous monitoring system technical requirements and detection methods) and technical specifications (national ambient air monitoring network ambient air volatile organic compounds continuous automatic monitoring quality control technical provisions (for trial implementation) web link). Which on the ambient air VOC online monitoring equipment, a variety of performance indicators, installation and acceptance conditions, quality control technology have made detailed provisions. As long as the instrument's performance indicators to meet these two standards, and after installation, in the premise of doing a good job in the maintenance work can be long-term stable operation is reliable. Domestic instruments, although a late start, but because of the large domestic demand for more applications and competition, so manufacturers can be prompted to carry out product technology to solve the problems found in the actual application of the problem. The advantage of domestic instruments is the fast response to repair and maintenance, foreign instrument parts may sometimes have to wait a few months, and for online instruments can not run for a few months is a big loss.
Perhaps before 2015, the domestic ambient air VOC monitoring equipment or manufacturers are less stable operation is generally inferior to foreign countries, but in recent years, with the decline in PM2.5 concentration, the ozone pollution problem is gradually highlighted, the country's attention to ozone pollution prompted by the gradual increase in the demand for monitoring of VOC components, which has led to the rapid development of domestic related instruments. In addition, there are standards and technical specifications as the basis, but also to promote the domestic instrumentation more and more standardized.
In summary, at present, the instruments of many manufacturers can meet the requirements of the standard (at present, it is by no means the only one in Wuhan Tianhong. Here to avoid the suspicion of advertising, I do not mention any other manufacturers.) As long as the maintenance of the instrument is in place, the quality control work is standardized, and the data is audited in a timely manner, the domestic equipment can also achieve a relatively good operating result.