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Suwalki
-NO2-
| Observation |
| Category |
: |
Air sampling observation |
| Situation |
: |
1994-03-31 |
| Time zone |
: |
UTC |
| Sampling |
| Sampling height |
: |
+3.0 |
| Description |
: |
continuous |
| Sampling and analysis frequency |
: |
Sampling was done in daily intervals. |
| Sampling environment |
: |
The station surrounded by meadows and woods is located in the Suwalki lake district.
The local road with medium vehicular traffic is situated 55m to the east of station building. A petrol station was build at the distance of 300m by the road in June 1992.
The sources are located as follows:
-Suwalki (city with 70 thousand inhabitants) 2.5km to S direction,
- Bialystok (city with 300 thousand inhabitants) 100km to S direction,
- Grodno (city with 300 thousand inhabitants)75km to SE direction,
- Kowno (city with 370 thousand inhabitants) 110km to NE direction,
- Augustow (town with 60 thousand inhabitants) 30km to S direction,
- Elk (town with 60 thousand inhabitants) 50km to SW direction.
The prevailing winds were from W and SW directions.
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| Description for sampling analysis |
: |
A manual low-volume sampler for NO2 measurement was used. Sampling inlet had quadratic cross-section. It was made of PE and mounted at the height of 3.0m above the ground level.The total length of teflon tubing (ID=6mm) was 2.7m. The air flow rate was 0.5l/min and the total volume of daily sample amounts to 0.7m3.
A precision wet gas meter was used for measuring the sampled air volume until June 1993. Since then the air flow rate was adjusted with use of a mass flow rate controller (ERG1000) calibrated by the producer once a year. The absorption efficiency was 80%.
Analyses were performed in monthly series.
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| Instrument and Analysis |
| Measurement method |
: |
Light absorption analysis (VIS) |
| Current status and history of instrument |
: |
Spectrophotometer Spekol 10 made by Carl Zeiss, Jena (German Democratic Republic) was used in period 1985-1988.
Spectrophotometer Spekol 11 made by Carl Zeiss, Jena (German Democratic Republic) was used in period 1989-1995.
Then spectrophotometer made by Hitachi, model U-1100,serial no. 0691-010 was used. |
| Description of instrument |
: |
Spectrophotometer made by HITACHI, model U-1100 enabled to achieve:
- analytical precision expressed as relative standard deviation (RSD):
1% at 0.304mgN-NO2/l
5.9% at 0.015mgN-NO2/l
- analytical detection limit: 0.008mgN-NO2/l
- measurement detection limit: 0.2µgN-NO2/m3 |
| Calibration |
| Current scale employed in the measurement |
: |
Scale of standards was prepared at the IMWM laboratory for monthly series of daily samples at the beginning of each month. |
| Measurement calibration |
: |
Spectrophotomerical analytical method was calibrated with use of standard nitrite solutions having the concentrations in the range of 0.0 - 2.0µgNO2/ml when each monthly series of collected daily samples was analysed. The calibration curve included from 8 to 10 points.
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| Scale and calibration(treasability) |
: |
Daily NO2 samples were taken at the regional background air pollution monitoring station. The NO2 concentration values measured at central laboratory were below 50µgNO2/m3. In the nineties annual mean NO2 concentration values calculated from the daily averages were much below 30µgNO2/m3, i.e. admissible value adopted by Polish Standard (March 1990) for specially protected areas.
Participation in the EMEP field intercomparison of methods for measuring NO2 at Kleiner Feldberg, Germany (1993).
Taking part in yearly EMEP laboratory intercomparisons of NO2 determination in several samples of synthetic aqueous solutions prepared by EMEP/CCC/NILU, Norway.
The detailed information and data on the quality assurance/quality control are presented on website:
www.nilu.no/projects/ccc/qa/index.htm
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| Data Processing |
| Measurement unit |
: |
µg/m3-20C, 1013hPa |
| Data processing |
: |
When the measured NO2 concentration was beyond the upper limit of the liner range of the calibration curve, the sample was appropriately diluted and reanalysed.
The raw daily data were stored in the data book and the data acquisition system.
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| Processing for averaging |
: |
Processing for Daily Data:
If the measured value was below the measurement detection limit i.e. 0.2µgN-NO2/m3, the half of this value was assumed.
Then the data were correlated with the meteorological data and with the information from the station logbook and other sources.
All incorrect and invalid daily data were rejected and marked in accordance with the appropriate codes specified in Data Reporting Manual of the WMO WDCGG (No.1), January 1991.
Processing for Monthly Data:
Arithmetic mean monthly values were calculated from valid daily data and were marked according to the appropriate codes for validation specified in Data Reporting Manual of the WMO WDCGG (No.1), January 1991. |
| Data flag |
: |
Flags specified by WDCGG in Data Reporting Manual (WDCGG No1, January 1991) were used. |
| Data remarks |
: |
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| Other Information |
| Scientific aim |
: |
To provide data for research and study to reveal long term trends in background NO2 concentrations in Poland in the framework of EMEP programme. |
| Reference |
: |
- EMEP co-operative Programme for Monitoring and Evaluation of the Long-range Transmission of Air Pollutants in Europe,
Manual for sampling and Chemical Analysis, EMEP/1/76, Norwegian Institute for Air Research (NILU) 1976.
-web site addresses:
www.emep.int/emep_title.html
www.nilu.no/projects/ccc/index.html
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| submitted by Institute of Meteorology and Water Management |
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