Quality Assurance of Air Quality Observation(空氣品質監測品質保證作業)line分享列印本頁
A. History

To ensure the accuracy and reliability of the data provided by the Air Quality Observation and Forecast Network , the EPA referred to the Quality Assurance (QA) program practiced by the US EPA and integrated the QA program into the design of the observation network when it started establishing the second generation network in 1988. In 1989, a management and operation system for Air Quality Observation and Forecast Network was established and a QA system and a QA lab were launched in 1991.

B. Quality Assurance System

Since the instruments are operated automatically and consecutively 24 hours a day, a QA program has been launched to ensure that all instruments are functioning normally. In 2001, the EPA formulated "Guidelines for the Quality Assurance of Air Quality Observation Facilities" to effectively utilize resources and to integrate the management of all regional air quality observation stations. The guidelines are :

(1) Standard operation procedures for air quality observation

(2) Routine QA procedures for air quality observation

(3) Requirements for gases and other items

(4) Goals for the quality of observation data

(5) The effectiveness of processing, documenting and submitting observation data

(6) Operation records of observation facilities

(7) Performance checks of observation instruments

(8) System checks

C. The Implementation of Quality Assurance

Quality Assurance is implemented to ensure the accuracy and precision of data provided, to achieve Data Quality Objectives (DQO), see table 3-1. Based on the QA program, the observation stations conduct monthly checks and an annual performance check on its pollutant analysis instruments and particulate analysis instruments. Some irregular checks are conducted when the instruments malfunction. Owing to the lack of human resources, the EPA started outsourcing QA programs in 1994 to conduct regular checks, annual performance checks, supervision and assessments of the effectiveness of data. Table 3-1 Data Quality Objectives (DQO)

The Implementation of Quality Assurance
Observation items Accuracy (deviation) coefficient slope intercept
Dynamic adjustment: flow of gas ≦ ±5% ≧ 0.995 N/A ±3%FS
Dynamic adjustment: flow of air ≦ ±5% ≧ 0.995 N/A ±3%FS
SO2 ≦ ±15% ≧ 0.995 0.85-1.15 ±3%FS
NOx ≦ ±15% ≧ 0.995 0.85-1.15 ±3%FS
Conversion rate of nitrogen dioxide 96% ≦ CE ≦ 102% N/A N/A N/A
CO ≦ ±15% ?≧ 0.995 0.85-1.15 ±3%FS
CO2 ≦ ±15% ?≧ 0.995 0.85-1.15 ±3%FS
O3 ≦ ±15% ?≧ 0.995 0.85-1.15? ±3%FS
HC ≦ ±15% ?≧ 0.995 0.85-1.15? ±3%FS
Flow of PM 10 ≦ ±10% N/A N/A N/A
Flow of PM 2. ≦ ±10% N/A N/A N/A
Wind velocity Zero 0.31 ≧ zero ≧ 0.24m/s (MET ONE) N/A N/A N/A
0.50m/s ≧ zero ≧ 0m/s
(new MET ONE)
0.25 ≧ zero ≧ 0 m/s (LASTEM)
0.25 ≧ zero ≧ 0 m/s (YOUNG)
0.25 ≧ zero ≧ 0 m/s (CLIMA)
?WS < 5m/s (Zero excluded) ≦ ±0.25m/s
WS ≧ 5m/s ≦ ±2%
Torque ≦ 0.35g-cm (0.5 m/s)
Wind direction WD ≦ ±5 degrees N/A N/A N/A
Torque ≦ 7g-cm (0.5 m/s)
Temperature ≦ ±0.5 ℃ N/A N/A N/A
Dew-point temperature ≦ ±2 ℃ N/A N/A N/A
Relative humidity ≦ ±5% N/A N/A N/A
Rainfall ≦ ±0.2mm N/A N/A N/A
Atsmopheric pressure ≦ ±5mmHg N/A N/A N/A
UVA ≦ ±5%W/m 2 N/A N/A N/A
UVB ≦±5%Index N/A N/A N/A
pH value of acid rain ≦±0.2pH N/A N/A N/A
Electric conduction of acid rain ≦±5% N/A N/A N/A
Acid rainfall ≦±0.5mm N/A N/A N/A
Environmental Protection Administration, R.O.C.(Taiwan)
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