Apogee Instruments MQ-620 소유자 매뉴얼 - 페이지 4

{카테고리_이름} Apogee Instruments MQ-620에 대한 소유자 매뉴얼을 온라인으로 검색하거나 PDF를 다운로드하세요. Apogee Instruments MQ-620 15 페이지. Quantum meter

Radiation that drives photosynthesis is called photosynthetically active radiation (PAR) and is typically defined as

total radiation across a range of 400 to 700 nm. PAR is almost universally quantified as photosynthetic photon flux

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density (PPFD) in units of micromoles per square meter per second (µmol m

, equal to microEinsteins per

square meter per second) summed from 400 to 700 nm (total number of photons from 400 to 700 nm). However,

ultraviolet and far red photons outside the defined PAR range of 400-700 nm can also contribute to photosynthesis

and influence plant responses (e.g., flowering).

Sensors that measure PPFD are often called quantum sensors due to the quantized nature of radiation. A quantum

refers to the minimum quantity of radiation, one photon, involved in physical interactions (e.g., absorption by

photosynthetic pigments). In other words, one photon is a single quantum of radiation. Sensors that function like

traditional quantum sensors, but measure a wider range of wavelengths can be thought of as an 'extended range'

quantum sensor.

Typical applications of traditional quantum sensors include incoming PPFD measurement over plant canopies in

outdoor environments or in greenhouses and growth chambers, and reflected or under-canopy (transmitted) PPFD

measurement in the same environments. The Extended Range PFD Sensor detailed in this manual uses a detector

that is sensitive to radiation up to about 1100 nm, well beyond the range of wavelengths that influence

photosynthesis and plant responses. This means this particular sensor should only be used for photon flux

density measurements under LEDs.

Apogee Instruments MQ-620 meters consist of a handheld meter and a dedicated sensor that is connected by

cable to an anodized aluminum housing. SQ-600 series Extended Range PFD Sensors consist of a cast acrylic

diffuser (filter), photodiode, signal processing circuitry mounted in an anodized aluminum housing, and are potted

solid with no internal air space. MQ series extended range PFD meters provide a real-time PFD reading on the LCD

display, that determine the radiation incident on a planar surface (does not have to be horizontal), where the

radiation emanates from all angles of a hemisphere. MQ series quantum meters include manual and automatic

data logging features for making spot-check measurements.