You are not currently logged in.
Access your personal account or get JSTOR access through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
A Cheap Quantum Sensor Using a Gallium Arsenide Photodiode
Vol. 4, No. 4 (1990), pp. 591-596
Published by: British Ecological Society
Stable URL: http://www.jstor.org/stable/2389327
Page Count: 6
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
A new quantum sensor for measuring photosynthetically active radiation (PAR) was designed using a gallium arsenide photodiode. This sensor is cheap and effectively measures radiation between 400 and 700 nm without any filter, which allows both high output level and easy manufacturing. A comparison with two other commercially available quantum sensors (Li-Cor and Macam sensors) was made. The sensor described here was less sensitive than the two others both in the blue and far-red parts of the spectrum. Its maximum sensitivity is near 600 nm. However it was shown, under natural light and several artificial light sources, that the results given by the three sensors were very similar. Nevertheless some problems could arise with monochromatic light sources such as sodium lamps whose spectrum is mainly composed of radiation between 570 and 620 nm. This study also shows that gallium arsenide sensors are suitable for PAR measurements under canopies.
Functional Ecology © 1990 British Ecological Society