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Cape Point
-O3-
| Observation |
| Category |
: |
Air sampling observation |
| Situation |
: |
ongoing |
| Time zone |
: |
UTC |
| Sampling |
| Sampling height |
: |
30 |
| Description |
: |
continuous |
| Sampling and analysis frequency |
: |
Continuous |
| Sampling environment |
: |
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| Description for sampling analysis |
: |
Sampling site is on top of a 230m coastal cliff. Air intake consists of a high volume fan drawing air through a 4m high glass tube from which a sub-sample is drawn to the instrument. Air passes through a 5 micron dust filter before reaching the instrument. Data: 1-min intervals are averaged and used to create half-hourly means. These in turn form the basis for daily and monthly means.
4-METRE GLASS AIR INTAKE |
| Instrument and Analysis |
| Measurement method |
: |
Light absorption analysis (UV) |
| Current status and history of instrument |
: |
UV Absorption |
| Description of instrument |
: |
Thermo Environmental Instruments TEI
TEI49C |
| Calibration |
| Current scale employed in the measurement |
: |
Travelling standard, traceable to NIST |
| Measurement calibration |
: |
Calibration (AUDIT): by EMPA,SWITZERLAND
Last Calibration (AUDIT): September 2006 |
| Scale and calibration(treasability) |
: |
TECO 49PS (Calibrated at EMPA)
Travelling standard, traceable to NIST |
| Data Processing |
| Measurement unit |
: |
ppb |
| Data processing |
: |
Data selection was applied to the "all data set" based on statistical filtering.
This was done in the following way:
11-day moving percentiles were applied to the data.
Two freely selectable percentiles, each tuneable by a factor, serve as upper and lower cut-off limits for background concentrations. |
| Processing for averaging |
: |
Processing for Hourly Data:
1-min data form the basis of half-hourly mean values.
Processing for Daily Data:
1-min data are averaged to form the basis of 30-min and daily mean values.The external zero values (determined daily) are factored into the daily means.
Processing for Monthly Data:
Raw data are processed at the end of each month. The external zero values - measured daily - are subtracted from the raw data. |
| Data flag |
: |
All data reported are valid. SPAN and Zero values are omitted from final reportrd data set. |
| Data remarks |
: |
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| Other Information |
| Scientific aim |
: |
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| Reference |
: |
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| submitted by South African Weather Service |
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