GENERATION, CONTROL, AND MEASUREMENT 147 



REFLECTION 



Reflection measurements are made in a manner similar to transmission 

 measurements. Total reflectance is defined as the ratio of reflected inten- 

 sity Ir to incident intensity h without regard to direction and includes 

 both the specularly and diffusely reflected flux; thus Ih/Io = total reflect- 

 ance. Specular reflectance involves only that flux which emerges from 

 the sample at an angle equal to the angle of incidence and does not include 

 scattered flux. 



REFERENCES 



Barrows, W. E. (1951) Light, photometry, and illuminating engineering. 3rd ed., 

 McGraw-Hill Book Company, Inc., New York. 



Brackett, F. S. (1936) Measurement and application of visible and near-visible 

 radiation. In Biological effects of radiation. Vol. I, McGraw-Hill Book Com- 

 pany, Inc., New York. Pp. 123-211. 



Brode, W. R. (1949) The presentation of absorption spectra data. J. Opt. Soc. 

 Amer., 39: 1022-1031. 



Crittenden, E. C. (1944) Units and conversion factors. In Medical physics, ed. 

 O. Glasser. Year Book Publishers, Inc., Chicago. Pp. 1596-1601. 



(1950) Units and conversion factors. In Medical physics, ed. O. Glasser. 



Vol. 2, Year Book Publishers, Inc., Chicago. Pp. XVII-XXIII. 



Daniels, F. (1948) Outlines of physical chemistry. John Wiley & Sons, Inc., New 



York. 

 Forsythe, W. E. (ed.) (1937) Measurement of radiant energy. McGraw-Hill Book 



Company, Inc., New York. 

 Gibson, K. S. (1949) Spectrophotometry. Natl. Bur. Standards U.S. Circ. 484. 

 Habell, K. J., and A. Cox (1948) Engineering optics. Sir Isaac Pitman & Sons, Ltd., 



London. 

 Illuminating Engineering Society (1942) Illuminating engineering nomenclature and 



photometric standards. ASA Z7.1, American Standards As.sociation, New York. 



(1952) lES lighting handbook. 2nd ed.. Illuminating Engineering Society, 



New York. 



International Commission on Illumination (1924) Proceedings of Sixth Session: 1-67. 



Judd, D. B. (1950) Colorimetry. Natl. Bur. Standards U.S. Circ. 478. 



Mellon, M. G. (ed.) (1950) Analytical absorption spectroscopy. John Wiley & Sons, 



Inc., New York. 

 Optical Society of America, Committee on Colorimetry (1944a) Physical concepts: 



radiant energy and its measurement. J. Opt. Soc. Amer., 34: 183-218. 



(1944b) The psychophysics of color. J. Opt. Soc. Amer., 34: 245-266. 



(1944c) Quantitative data and methods for colorimetry. J. Opt. Soc. Amer., 



34: 633-688. 



(1953) The science of color. Thomas Y. Crowell Company, New York. 



Pirie, N. W. (1951) The clear representation of very small masses. Nature, 168: 

 1008. 



Rabinowitch, E. I. (1945) Photosynthesis and related processes. Vol. I, Inter- 

 science Publishers, Inc., New York. 



Richtmyer, F. K., and E. H. Kennard (1947) Introduction to modern physics. 

 4th ed., McGraw-Hill Book Company, Inc., New York. 



Weaver, K. S. (1937) The visibility of radiation at low intensities. J. Opt. Soc. 

 Amer., 27: 36-43. 



Withrow, R. B. (1943) Radiant energy nomenclature. Plant Physiol., 18: 476-487. 



