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| 
Pleven
-NO2-
| Observation |
| Category |
: |
Air sampling observation |
| Situation |
: |
ongoing |
| Time zone |
: |
UTC |
| Sampling |
| Sampling height |
: |
|
| Description |
: |
continuous |
| Sampling and analysis frequency |
: |
Several times a day |
| Sampling environment |
: |
|
| Description for sampling analysis |
: |
Sampling duration is 1/2 hour. Four samples per day are made, at 6, 9, 12 and 15 UTC.
Single beam spectrometer with continuous spectrum and manual adjustment of the beam. Spectral interval is 350-850 nm. Measurement for NO2 is performed at 520 nm. |
| Instrument and Analysis |
| Measurement method |
: |
|
| Current status and history of instrument |
: |
Spectrophotometer |
| Description of instrument |
: |
Karl Zeiss, Jena
SPECOL 11 |
| Calibration |
| Current scale employed in the measurement |
: |
|
| Measurement calibration |
: |
The method is photometric. Standard solutions are prepared at the stations every 3 days. A calibration curve is plotted and used in measurement procedure. The sensitivity of the method is 0.1 microgram per 3 ml measured solution. A solution of Griss' reagent is used during the measurements. The relative error of the method is 15%. the method is registered under Bulgarian State Standard (BSS)-BSS 17.2.4.22-83. |
| Scale and calibration(treasability) |
: |
Bulgarian State Standard (BSS)-BSS 17.2.4.22-83 |
| Data Processing |
| Measurement unit |
: |
mg/m3-25C |
| Data processing |
: |
|
| Processing for averaging |
: |
Processing for Daily Data:
Arithmetic mean from the four measurements.
Processing for Monthly Data:
Arithmetic mean of the daily data. |
| Data flag |
: |
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| Data remarks |
: |
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| Other Information |
| Scientific aim |
: |
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| Reference |
: |
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| submitted by National Institute of Meteorology and Hydrology |
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