The principle and operation of a photometer using photoconductive (cadmium sulphide) cells are described. Some limitations of the instrument were detected and these are discussed in relation to the photoconductivity of CdS cells. Some inherent characteristics of the dynamic equilibrium of a CdS cell, which apply under all conditions, make it difficult to keep this type of photometer in calibration. Suggestions are outlined to help users to overcome these difficulties, and modifications are proposed for future designs.
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References
1.
Guha, S.K., J. Phys. E, Sci. Instrum., 5 (2), 145 (1972).
2.
Smith, W., Nature, 7, 303 (1873).
3.
Moss, T.S., Photoconductivity in the elements, Butterworth , London (1952).
4.
Bube, R.H., Photoconductivity of solids, John Wiley & Sons , New York and London (1960).
5.
Heijne, L., Philips tech. Rev., 27, 47 (1966).
6.
Kulp, B.A., J. Appl. Phys., 36, 553 (1965).
7.
Rose, A., Concepts in photoconductivity and allied problems, John Wiley & Sons, New York and London (1963).
8.
van der Ziel, Solid state physical electronics, 2nd ed., Prentice Hall, New York (1968).
