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METHODS FOR THE PHOTO‐ELECTRIC AND PHOTO‐CHEMICAL MEASUREMENT OF DAYLIGHT 1
Author(s) -
ATKINS W. R. G.,
POOLE H. H.
Publication year - 1930
Publication title -
biological reviews
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.993
H-Index - 165
eISSN - 1469-185X
pISSN - 1464-7931
DOI - 10.1111/j.1469-185x.1930.tb00894.x
Subject(s) - photometer , photometry (optics) , daylight , optics , electric field , galvanometer , environmental science , materials science , physics , stars , quantum mechanics , astronomy , laser
Summary. The optical conditions relating to plane, cylindrical, and spherical photometers are discussed. A brief account is given of some galvanometers found to be suitable for the measurement of the photo‐electric current in the field, of the potentiometer method for use at sea, and of the use of a recording galvanometer for continuous measurement of the variations of daylight. The current may be integrated over a short period by timing the flashes of a neon lamp shunted by a condenser, or, over longer periods, by the electrolytic deposition of copper. Types of photo‐electric cells are discussed in relation to their spectral sensitivity, constancy and standardisation. Examples are given of photo‐electric measurements of daylight in the open, in buildings, in woods, and down to 70 metres depth in the open sea. A brief description is given of photo‐chemical photometry by means of uranyl oxalate solutions and its standardisation against photo‐electric measurements. The methylene blue method of ultra‐violet photometry is also mentioned.