{"id":5393,"date":"2020-06-29T01:15:07","date_gmt":"2020-06-29T01:15:07","guid":{"rendered":"http:\/\/rocker.designhu-demo.com\/application\/air_sampling\/"},"modified":"2026-03-09T11:00:14","modified_gmt":"2026-03-09T03:00:14","slug":"air_sampling","status":"publish","type":"application","link":"https:\/\/www.rocker.com.tw\/en\/application\/air_sampling\/","title":{"rendered":"Air sampling"},"content":{"rendered":"
Contents<\/strong><\/span>
\nWhat is air sampling?<\/a>
\nSubstances sampled in air sampling and air quality standards<\/a>
\nAir Sampling techniques<\/a>
\nActive sampling<\/a>
\nPassive sampling<\/a>
\nDifferences between air sampling and air monitoring<\/a>
\nAir sampling applications<\/a><\/div>\n

 <\/p>\n

 <\/p>\n

<\/a>What is air sampling?<\/h2>\n

 <\/p>\n

What is air sampling? Air is a necessary condition for human survival. With the development of industrial civilization, the demand for quality of life has been increasing, and the monitoring of air quality has become one of the important issues in recent years. High concentrations of pollutants in the air, such as fine particulate matter (PM 2.5, PM 10), carbon dioxide (CO2), carbon monoxide (CO), volatile organic compounds (VOCs), and microbes, not only pose risks to human health but may also impact environmental changes. Therefore, air sampling is used to assess air quality, understand pollutant concentrations and compositions in the atmosphere, and monitor environmental changes in order to formulate improvement measures.
\nAir sampling refers to the collection of quantified volumes of air samples, which are then analyzed using appropriate methods to determine the concentrations of pollutants such as particulates and microbes. This process is used to evaluate air quality, identify potential sources of pollution, and monitor environmental changes.<\/p>\n

 <\/p>\n

\n

 <\/p>\n

<\/a>Substances sampled in air sampling and air quality standards<\/h2>\n

 <\/p>\n

Air sampling can be applied in a wide range of areas, including indoor public places such as libraries, art galleries, KTVs, gyms, and outdoor environments such as industrial areas, major transportation routes, and agricultural areas. Whether in indoor or outdoor spaces, poor air quality can cause discomfort or damage to respiratory, visual, and other organs, as well as the central nervous system. Common pollutants in the air include inorganic substances such as carbon dioxide, carbon monoxide, sulfur dioxide, organic compounds such as formaldehyde, total volatile organic compounds, and biological particles such as bacteria, fungi, and fine particulate matter.<\/p>\n

In order to protect public health and prevent health issues caused by air quality, the Ministry of Environment (R.O.C.)<\/span> has established corresponding regulations, such as the “Air Quality Standards” (No. 1131062467) and the “Indoor Air Quality Standards” (No. 1010106229). The types and standard values of these regulations are shown in the table below:<\/p>\n\n\n\n\n\n\n\n\n\n\n\n
\n

Air Quality Standards<\/strong><\/p>\n<\/td>\n<\/tr>\n

\n

Item<\/p>\n<\/td>\n

\n

Standard<\/p>\n<\/td>\n

\n

Unit<\/p>\n<\/td>\n<\/tr>\n

\n

PM 10<\/p>\n<\/td>\n

\n

75b<\/sup><\/p>\n<\/td>\n

\n

\u03bcg\/m\u00b3<\/p>\n<\/td>\n<\/tr>\n

\n

PM 2.5<\/p>\n<\/td>\n

\n

30b<\/sup><\/p>\n<\/td>\n

\n

\u03bcg\/m\u00b3<\/p>\n<\/td>\n<\/tr>\n

\n

SO2<\/sub>\u00a0<\/p>\n<\/td>\n

\n

0.065a<\/sup><\/p>\n<\/td>\n

\n

ppm<\/p>\n<\/td>\n<\/tr>\n

\n

NO2<\/sub><\/p>\n<\/td>\n

\n

0.100a<\/sup><\/p>\n<\/td>\n

\n

ppm<\/p>\n<\/td>\n<\/tr>\n

\n

Carbon monoxide (CO)<\/p>\n<\/td>\n

\n

31a<\/sup><\/p>\n<\/td>\n

\n

ppm<\/p>\n<\/td>\n<\/tr>\n

\n

O3<\/p>\n<\/td>\n

\n

0.100a<\/sup><\/p>\n<\/td>\n

\n

ppm<\/p>\n<\/td>\n<\/tr>\n

\n

Pb<\/p>\n<\/td>\n

\n

0.15c<\/sup><\/p>\n<\/td>\n

\n

\u03bcg\/m\u00b3<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Note<\/p>\n

a<\/sup>1-hour value: Refers to the arithmetic mean of various measured values within one hour<\/p>\n

b<\/sup>24-hour value: Refers to the sample obtained through continuous sampling over a period of twenty-four hours and the value obtained after analysis<\/p>\n

c<\/sup>3-month moving average: Refers to the arithmetic mean of the average values of valid data for three consecutive months.<\/p>\n

 <\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n
\n

Indoor Air Quality Standards<\/strong><\/p>\n<\/td>\n<\/tr>\n

\n

Item<\/p>\n<\/td>\n

\n

Standard<\/p>\n<\/td>\n

\n

Unit<\/p>\n<\/td>\n<\/tr>\n

\n

CO2<\/sub><\/p>\n<\/td>\n

\n

1000b<\/sup><\/p>\n<\/td>\n

\n

ppm<\/p>\n<\/td>\n<\/tr>\n

\n

CO<\/p>\n<\/td>\n

\n

9b<\/sup><\/p>\n<\/td>\n

\n

ppm<\/p>\n<\/td>\n<\/tr>\n

\n

CH2<\/sub>O<\/p>\n<\/td>\n

\n

0.08a<\/sup><\/p>\n<\/td>\n

\n

ppm<\/p>\n<\/td>\n<\/tr>\n

\n

TVOC*<\/p>\n<\/td>\n

\n

0.56a<\/sup><\/p>\n<\/td>\n

\n

ppm<\/p>\n<\/td>\n<\/tr>\n

\n

Bacteria<\/p>\n<\/td>\n

\n

1500d<\/sup><\/p>\n<\/td>\n

\n

CFU\/m\u00b3<\/p>\n<\/td>\n<\/tr>\n

\n

Fungi<\/p>\n<\/td>\n

\n

1000**,d<\/sup><\/p>\n<\/td>\n

\n

CFU\/m\u00b3<\/p>\n<\/td>\n<\/tr>\n

\n

PM 10<\/p>\n<\/td>\n

\n

75c<\/sup><\/p>\n<\/td>\n

\n

\u03bcg\/m\u00b3<\/p>\n<\/td>\n<\/tr>\n

\n

PM 2.5<\/p>\n<\/td>\n

\n

35c<\/sup><\/p>\n<\/td>\n

\n

\u03bcg\/m\u00b3<\/p>\n<\/td>\n<\/tr>\n

\n

O3<\/sub><\/p>\n<\/td>\n

\n

0.06b<\/sup><\/p>\n<\/td>\n

\n

ppm<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Note:\u00a0<\/p>\n

*Total volatile organic compounds, including the sum of twelve volatile organic compounds: It refers to the standard value of total volatile organic compounds, which is the sum of concentration measurements of twelve compounds, namely benzene, carbon tetrachloride, chloroform (also known as trichloromethane), 1,2-dichlorobenzene, 1,4-dichlorobenzene, dichloromethane, ethylbenzene, styrene, tetrachloroethylene, trichloroethylene, toluene, and xylene<\/p>\n

**Fungal concentration indoor\/outdoor ratio less than or equal to 1.3 is not subject to this limitation.<\/p>\n

a<\/sup>1-hour value: Refers to the arithmetic mean of various measured values within one hour<\/p>\n

b<\/sup>8-hour value: Refers to the sample obtained through continuous sampling over a period of eight hours and the value obtained after analysis<\/p>\n

c<\/sup>24-hour value: Refers to the sample obtained through continuous sampling over a period of twenty-four hours and the value obtained after analysis<\/p>\n

d<\/sup>Highest value: Refers to the sampling analysis value obtained through the sampling method specified in the testing methods announced by the competent authority<\/p>\n

 <\/p>\n

\n

 <\/p>\n

<\/a>Air sampling techniques<\/h2>\n

 <\/p>\n

Sampling is the first step in all types of detection, and air sampling methods can be classified into active sampling and passive sampling based on their collection principles. Active sampling is widely adopted by most international official guidelines because it allows for the collection of quantitative gases at a controlled flow rate. The principles, advantages, and disadvantages of active and passive sampling are compared in the table below:<\/p>\n

 <\/p>\n\n\n\n\n\n
\n

Method<\/p>\n<\/td>\n

\n

Principle<\/p>\n<\/td>\n

\n

Advantage<\/p>\n<\/td>\n

\n

Disadvantage<\/p>\n<\/td>\n<\/tr>\n

\n

Active sampling<\/p>\n<\/td>\n

\n

Collect air samples from a container using vacuum or fan\u00a0<\/p>\n<\/td>\n

\n

Flow and time are both adjustable, thus is<\/p>\n

\u2022 Faster to collect<\/p>\n

\u2022 More accurate results<\/p>\n

\u2022 Can be quantitative or qualitative<\/p>\n

\u2022 Suitable for both particle or gas-form samples<\/p>\n

\u2022 Adopted by most governments’ official guidelines<\/p>\n<\/td>\n

\n

\u2022 Only daily average data can be obtained<\/p>\n

\u2022 Regular calibration of instruments is required<\/p>\n

\u2022 Easily disturbed by air flow<\/p>\n

\u2022 More costly equipment<\/p>\n

\u2022 Driver required<\/p>\n<\/td>\n<\/tr>\n

\n

Passive sampling<\/p>\n<\/td>\n

\n

Air particles are adhered to absorbent and collected based on its natural diffusion and permeation\u00a0<\/p>\n<\/td>\n

\n

\u2022 Less costly<\/p>\n

\u2022 Simple procedure<\/p>\n

\u2022 Effective in longer term detection<\/p>\n

\u2022 Can be collected in multiple locations simultaneously<\/p>\n

\u2022 No air flow disturbance<\/p>\n

\u2022 Collected samples are more similar to actual condition<\/p>\n

\u2022 No driver required<\/p>\n<\/td>\n

\n

\u2022 Only monthly\/weekly average data can be obtained<\/p>\n

\u2022 Time-consuming<\/p>\n

\u2022 For gas-form samples only<\/p>\n

\u2022 Semi-quantitative only<\/p>\n

\u2022 Not being adopted by most officials<\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

 <\/p>\n

<\/a>Active air sampling\u00a0<\/h3>\n

Active air sampling can be further divided into direct and indirect methods, with differences in their configurations. However, both methods share a basic framework consisting of a driving force (pump, fan), collection container (impinger, impactor, sampling bag), and the selection of appropriate adsorbents (collection liquid, culture media) based on the collection container and sampling method.<\/p>\n

Collect with impinger<\/h4>\n

An impinger is a specially designed glass bubbler that collects chemical substances from the air into a liquid medium. During sampling, a pump draws a known volume of air into the impact bottle containing the designated collection liquid, causing the air to bubble quantitatively. This allows the chemical substances to dissolve in the liquid, achieving the purpose of sample collection.<\/p>\n

<\/p>\n

 <\/p>\n

Collect with impactor<\/h4>\n

Impactors are commonly used to analyze microorganisms in the air, such as bacteria and fungi. An impactor utilizes a vacuum pump or a fan to draw in air and create an airflow, allowing the microorganisms in the air to pass through holes or narrow gaps on the sampling head and attach to a solid medium, such as agar gel culture medium. Subsequently, the microorganisms’ growth can be observed through cultivation, and the microbial content in the air can be assessed.
\nThis device is typically employed for environmental monitoring in cleanrooms, medical facilities, and farms.<\/p>\n

 <\/p>\n

Collect with sample bag<\/h4>\n

Air sampling bags, also known as gas sampling bags, air collection bags, or gas sample bags, can be classified into direct sampling and indirect sampling methods based on the sampling approach.
\nFor general gas sampling, direct sampling is typically sufficient. However, in harsh or highly polluted environments, indirect sampling can be performed using air sampling boxes to reduce contamination of the pump and the sample.<\/p>\n