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Krvavec
-CO-
| Observation |
| Category |
: |
Air sampling observation |
| Situation |
: |
ongoing |
| Time zone |
: |
Local time +1 |
| Sampling |
| Sampling height |
: |
10 |
| Description |
: |
continuous |
| Sampling and analysis frequency |
: |
Continuous air flow of 1.5 litres per minute through the CO instrument and data are analysed every 60 seconds. |
| Sampling environment |
: |
Krvavec monitoring site is situated at the altitude of 1600 m, surrounded mostly by short grass, and under 1600 m partly with coniferous forest. Surrounding slopes and peaks are rocky (limestone). It is located cca. 30 km north of Ljubljana city on mountain crest on the edge of eastern Alps (Kamniško Savinjske alpe – mountain crest with peaks reaching 1500 to 2500 m). Monitoringt site lies above the cold surface air layer, which occurs frequently over the Ljubljana basin during wintertime. Sometimes during anticyclonal situations the inversion layer may rise higher so that the monitoring site lies inside the inversion layer. In heating and skiing period of the year during special weather conditions (weak South to South-East wind) the skiing center and small villages lying beneath Krvavec may slightly contribute to the local air pollution. |
| Description for sampling analysis |
: |
Automatic sampling
NDIR-absorption
Air is sampled through the glass tube at 10 m height. The sampled air is introduced to a CO instrument.
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| Instrument and Analysis |
| Measurement method |
: |
NDIR |
| Current status and history of instrument |
: |
14.11.05 – present; APMA 360; Serial nr.: 205003, ID 7062; Horiba |
| Description of instrument |
: |
Standard ranges: 5, 10, 20, 50 ppm, or 10, 20, 50, 100 ppm
Lower detection limit: 0.05 ppm (2 sigma) (5 ppm range)
Repeatability: Within ± 1.0% of full scale
Accuracy of graduation: Within ± 1.0% of full scale
Zero drift:
- Larger one of ± 0.1 ppm per day or ± 1.0% of full scale value per day
- Larger one of 0.2 ppm per day or ± 2.0% of full scale value per week
Span drift: ± 2.0% of full scale value per day
± 3.0% of full scale value per week
Response time T90: Within 60 s from system inlet
Interference effect: ± 0.3 ppm for 2 vol% H2O and 1000 ppm CO2
Sampling flow rate: Approx. 1.5 L/min
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| Calibration |
| Current scale employed in the measurement |
: |
Observers standard scale, traceable to CHMI |
| Measurement calibration |
: |
The zero level of the instrument is checked every 24,5 hours. The zero gas from zero air generator and span gas from calibrated bottle (9ppm CO in air) is introduced every 24,5 hours.
The span gas from the calibrated bottle and zero air are 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 2 spans. In addition also ‘type approval’ tests (short term drift, response time, linearity and repeatability) are also performed annually.
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| Scale and calibration(treasability) |
: |
The certified reference materials (CRMs) are bottles with 7000 and 15000 ppb and are certified at CHMI accredited laboratory once per year and are therefore traceable to international level. The latest calibration was performed in 2011.
The transfer standard (MLU Model 300) is calibrated against laboratory’s CRMs every year.
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. |
| 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 2nd level control and flagging is performed by responsible person. All invalid half an hourly data are eliminated. Valid data coverage must be at least 75%.
Valid data is reported. Flags indicate the status of the data.
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| Processing for averaging |
: |
Processing for Hourly Data:
Hourly data are generated as arithmetic means of the checked valid half an hour data.
Processing for Daily Data:
Daily data are generated as arithmetic means of valid hourly data. Valid data coverage must be at least 75%.
Processing for Monthly Data:
Monthly CO data were calculated by averaging the valid daily data untill 2010. Valid data coverage was at least 75%.
Monthly CO 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 |
: |
EMEP flags have been used. Definition 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). |
| Data remarks |
: |
/ |
| Other Information |
| Scientific aim |
: |
To provide data for research and study, and to evaluate long term trends.
|
| Reference |
: |
- Operation manual - Ambient CO Monitor - APMA-360, Horiba, Ltd.
- Maintenance manual - Ambient CO Monitor - APMA-360, Horiba, Ltd.
- Installation manual - Ambient CO Monitor - APMA-360, Horiba, Ltd. |
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| submitted by Slovenian Environment Agency |
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