PLANT CHLOROPHYLL CONTENT METER

摘要

A plant chlorophyll content meter (100) collects light reflected from a target plant and separates the collected light into two different wavelength bands. These wavelength bands, or channels, have center wavelengths of 700 nm and 840 nm. The light collected in these two channels are processed using photodetectors (110, 112) and amplifiers (114, 116, 118, 120). An analog to digital converter (126) provides a digital representation of the level of light collected by the lens (102) and falling within the two channels. A controller (130) provided in the meter device compares the level of light reflected from a target plant with a level of light detected from a light source, such as light reflected by a target having 100 % reflectance, or transmitted through a diffusion receptor. The percent of reflection in the two separate wavelength bands from the target plant are compared to provide a ratio which indicates a relative level of plant physiological stress.