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Iskrba
-O3-
| Observation |
| Category |
: |
Air sampling observation |
| Situation |
: |
ongoing |
| Time zone |
: |
Local time 1 |
| Sampling |
| Sampling height |
: |
4 |
| Description |
: |
continuous |
| Sampling and analysis frequency |
: |
Continuous air flow of 0.745 litres per minute through the ozone instrument and data is analysed every 60 seconds. |
| Sampling environment |
: |
Iskrba monitoring site is a regional station, part of the Slovenian national monitoring network for monitoring the background air polution. It is located on a plateau at approximately 500 m a.s.l. in a prevalently woody area and within the continental climat zone. The plateau is surrounded by hills and mountains of approximately 800-1200 m a.s.l.. The surrounding area is mostly wooded (prevailingly coniferous trees). The rest is grass land (meadows) and partly also pastures. |
| Description for sampling analysis |
: |
UV-absorption
Automatic sampling. Air is sampled through the glass tube at 4 m height into the instrument.
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| Instrument and Analysis |
| Measurement method |
: |
Light absorption analysis (UV) |
| Current status and history of instrument |
: |
16.03.05 - present; Model 49C; Serial nr.: 60330-326, ID 372; TEI Inc. |
| Description of instrument |
: |
Custom ranges:
Range: 50; 100; 200; 500; 1000; 2000; 5000 ppb
Zero noise: 0.5 ppb RMS
Lower detectable limit: 1.0 ppb
Response time: 20 seconds (0-95%)
LAG time: 10 seconds
Precision: 1ppb
Linearity: ±1 % Fullscale
Flow rate: 1-3 liters/min
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| Calibration |
| Current scale employed in the measurement |
: |
Observers standard scale, traceable to CHMI |
| Measurement calibration |
: |
Gases from the Internal Zero Span System are introduced every 24,5 hours (30, 50, 80, 100). The span gas from the working standard instrument is introduced once every three months on the field.
Instrument is calibrated in accredited calibration laboratory once per year. The span gas is introduced at zero level and 4 spans. In addition also ‘type approval’ tests (short term drift, response time, linearity and repeatability) are also performed annually.
The mole fractions are determined by the linear regression line from zero level and the 4 spans.
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| Scale and calibration(treasability) |
: |
A calibration laboratory’s primary/reference standard UV photometer ozone generator (Thermo Environmental Instruments 49C PS) is calibrated at CHMI every year and therefore traceable to international level.
The transfer standard ozone generator (MLU) is calibrated by Accredited Calibration laboratory once a year against primary standard.
The instrument is regularly calibrated 4 times per year:
- against primary standard once in accredited laboratory,
and the rest
- against transfer standard on field.
Intercomparison in Evaluation of the Laboratory Comparison
Exercise for SO2, CO, O3, NO and NO2 is attended every 2 years.
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| Data Processing |
| Measurement unit |
: |
ppb |
| Data processing |
: |
The raw data from the instrument are collected on the local PC, and stored in the system as one minute raw data. In the 1st level automatic control takes place and all invalid data are flagged. Half an hour data are calculated from valid minute data and transferred to the database on ARSO where the 2nd level control and flagging is performed by responsible person. All invalid half an hour data are eliminated. Valid data coverage must be at least 75%. |
| Processing for averaging |
: |
Processing for Hourly Data:
Hourly data are generated as arithmetic means from checked valid half an hour data. Valid data coverage must be at least 75%.
Processing for Daily Data:
Daily data are generated as arithmetic means from valid hourly data. Valid data coverage must be at least 75%.
Processing for Monthly Data:
Monthly O3 data were calculated by averaging the valid daily data untill 2010. Valid data coverage was at least 75%.
Monthly O3 data are calculated by averaging the valid hourly data from 2011 on. Valid data coverage must be at least 75%.
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| Data flag |
: |
Flags According to EEA/DEM (European Environment Agency/Data Exchange Module) were used until the end of the year 2002.
EMEP flags have been used from the beginning of the year 2003. List of flags is available on EMEP homepage / CCC / Data submission / List of flags used in EMEP data base (http://www.nilu.no/projects/ccc/submission.html).
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| Data remarks |
: |
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| Other Information |
| Scientific aim |
: |
To provide data for research and study as well as to define long term trends. |
| Reference |
: |
EMEP manual for sampling and chemical analysis (EMEP/CCC-Report 1/95, Reference: O-7726, Norwegian Institute for Air Research, Date: March 1996, Revision: November 2001) (http://www.nilu.no/projects/ccc/manual/index.html). |
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| submitted by Slovenian Environment Agency |
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