Apogee Instruments S2-432 소유자 매뉴얼 - 페이지 4

{카테고리_이름} Apogee Instruments S2-432에 대한 소유자 매뉴얼을 온라인으로 검색하거나 PDF를 다운로드하세요. Apogee Instruments S2-432 18 페이지. Red-far-red sensors

INTRODUCTION

Specific wavelengths of radiation trigger distinct responses in plants. Red and far-red wavelengths are of particular

interest because they influence photosynthetic and morphogenic activity. Phytochrome pigments in plants are

sensitive to varying ratios of red and far-red radiation, providing information to the plant about the light

environment, and therefore, optimal growth patterns. Increasing the fraction of red radiation indicates less

shading and generally results in more conservative vertical growth patterns, while increasing the far-red radiation

fraction indicates more shading and results in more aggressive vertical growth patterns.

Red - far-red sensors are designed to have spectral sensitivities that approximate the phytochrome absorption

spectrum. Red - far-red sensors quantify properties of radiation sources, not plant responses. However, inferences

of plant responses can be made from measurements of the lighting/shading environment, so it is important that

red - far-red sensors have high sensitivity in the wavelength ranges where plants are most sensitive (i.e., the

wavelength ranges that drive the strongest responses in plants), hence red - far-red sensor spectral responses

should approximate the phytochrome absorption spectrum.

The primary application of red - far-red sensors is monitoring plant light environments, including calculation of the

red to far-red ratio (red photon flux density / far-red photon flux density) and far-red fraction (far-red photon flux

density / sum of red and far-red photon flux densities), in photobiology studies (e.g., researching plant

morphogenic activities).

Apogee Instruments S2 series Red - Far-red sensors consist of a cast acrylic diffuser, pair of photodiodes that

measure specific wavelength ranges, and signal processing circuitry mounted in an anodized aluminum housing,

and a cable to connect the radiometer to a measurement device. Sensors are potted solid with no internal airspace

and are designed for continuous measurement in indoor and outdoor environments. S2-100 series sensors output

two analog voltages, one for each photodetector, that are directly proportional to red and far-red radiation

incident on a planar surface (does not have to be horizontal), where the radiation emanates from all angles of a

hemisphere. The S2-432 model outputs a digital signal using Modbus RTU communication protocol over RS-232 or

RS-485.