Innovative high concentration VOCs sampler can be used in high temperature, high humidity, high dust and strong corrosivity. The high concentration VOCs sample gas is diluted to low concentration by two stages, and then enters the sampling tank for storage. Compared with the traditional vacuum box + air bag sampling method, it avoids the shortcomings of air bag sampling in adsorption and permeability, as well as the problem of short sample storage time.
Compared with the air bag sampling method, the absorption of the sampling tank is very low, basically no permeability, and the concentration loss of the sample is the least, which can reflect the real concentration of VOCs emission.
Two stage dilution avoids the problem of high temperature and high humidity of the original sample. The dilution ratio is flexible and adjustable, the sample does not pollute the sampling tank, and the sampling tank can be reused for many times.
The built-in PID detector can measure the concentration of VOCs after primary dilution, further determine the dilution ratio of the second stage, and ensure that the final concentration into the sampling tank is within the appropriate range.
Under the influence of temperature and humidity, the samples collected by the air bag method need to be kept at 120 ℃ for the whole process before analysis. After the sampler is diluted, there is no such problem. The whole process is more convenient from sampling to transportation to laboratory storage.
The storage time of air bag collected samples is very short. Hj732-2014 requires 8 hours to complete the analysis, and hj38-2017 requires 48 hours to complete the analysis. It can be stored in a large number of sampling tanks for one month.
The aluminum foil sampling bag is suitable for collecting halogenated hydrocarbons with boiling point below 60 ℃; teldar bag can be used to collect halogenated aliphatic hydrocarbons and benzene series with boiling point lower than 150 ℃, which is not suitable for sampling of halogenated aromatic hydrocarbons; and the sampling tank can collect more than 100 kinds of substances, with more types of substances.
Perfect quality assurance measures: with the function of recovery test to ensure the accuracy of dilution.
High concentration VOCs sample sampling: petroleum refining, petrochemical, coal chemical, electronic industry, textile printing and dyeing, printing and packaging, pesticide, pharmaceutical, coating, wood-based panel, storage tank pipeline, coating.