Apogee SQ-205X Посібник користувача - Сторінка 13

Переглянути онлайн або завантажити pdf Посібник користувача для Аксесуари Apogee SQ-205X. Apogee SQ-205X 19 сторінок. Quantum sensor

Spectral Errors

Apogee SQ-100X series sensors can measure PPFD for sunlight and electric light with a single calibration factor.

However, errors occur in various light sources due to changes in spectral output. If the light source spectrum is

known then errors can be estimated and used to adjust the measurements. The weighting function for PPFD is

shown in the graph below, along with the spectral response of Apogee SQ-100X series quantum sensors. The closer

the spectral response matches the defined PPFD spectral weighting functions, the smaller spectral errors will be.

The table below provides spectral error estimates for PPFD measurements from light sources different than the

calibration source. The method of Federer and Tanner (1966) was used to determine spectral errors based on the

PPFD spectral weighting functions, measured sensor spectral response, and radiation source spectral outputs

(measured with a spectroradiometer). This method calculates spectral error and does not consider calibration,

cosine, and temperature errors.

Federer, C. A., and C. B. Tanner, 1966. Sensors for measuring light available for photosynthesis. Ecology 47:654-

657.

McCree, K. J., 1972. The action spectrum, absorptance and quantum yield of photosynthesis in crop plants.

Agricultural Meteorology 9:191-216.