Apogee MU-100 소유자 매뉴얼 - 페이지 10
{카테고리_이름} Apogee MU-100에 대한 소유자 매뉴얼을 온라인으로 검색하거나 PDF를 다운로드하세요. Apogee MU-100 15 페이지. Ultraviolet meter
Apogee MU-100에 대해서도 마찬가지입니다: 매뉴얼 (3 페이지)
페이지 인쇄
10
MAINTENANCE AND RECALIBRATION
Moisture or debris on the sensor is a common cause of low readings. The sensor has a domed-shaped housing for improved
self-cleaning from rainfall, but materials can accumulate on the photo-sensitive area (e.g., dust during periods of low rainfall,
salt deposits from evaporation of sea spray or sprinkler irrigation water) and partially block the optical path. Dust or organic
deposits are best removed using water, or window cleaner and a soft cloth or cotton swab. Salt deposits should be dissolved
with vinegar and removed with a soft cloth or cotton swab. Never use an abrasive material or cleaner on the sensor.
The Clear Sky Calculator (www.clearskycalculator.com) determines total shortwave radiation or photosynthetic photon flux
density (PPFD) incident on a horizontal surface at any time of day at any location in the world. It is most accurate when used
near solar noon in spring and summer months, where accuracy over multiple clear and unpolluted days is estimated to be ±
4 % in all climates and locations around the world.
Although the Clear Sky Calculator does not specifically report an estimated value for UV radiation, it can still be used to help
determine the need for UV sensor recalibration by approximating the ratio of UV to total shortwave or the ratio of UV to
PPFD. However, due to continuous changes in atmospheric conditions and their effect on UV radiation, the comparison of
the UV sensor to the Clear Sky Calculator should only be made in the summer months near solar noon, and under completely
clear skies.
To calculate a reference value of UV radiation in units of energy flux (W m
), input site conditions into the calculator to
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determine the estimated total shortwave radiation. Then multiply the estimated total shortwave value by an approximated
ratio value between 0.045 and 0.050 to convert the total shortwave radiation to total UV radiation.
To calculate a reference value of UV radiation in units of photon flux density (μmol m
s
), input site conditions into the
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calculator to determine the estimated PPFD. Then multiply the estimated PPFD by an approximated ratio value between
0.070 and 0.075 to convert the PPFD to total UV radiation.
If UV sensor measurements over multiple days near solar noon are consistently different than calculated values (by more
than 10 %), the sensor should be cleaned and re-leveled. If measurements are still different after a second test, email
to discuss test results and possible return of sensor(s).