Photographic plates and films

A variety of methods have been devised to detect emissions from radioactive substances. Becquerel discovered radioactivity because of the effect of radiation on photographic plates. Photographic plates and film have long been used to detect radioactivity. The radiation affects photographic film in much the same way as X rays do. With care, film can be used to give a quantitative measure of... 

Mass spectrograph. An instrument in which beams of ions are separated according to their mass-to-charge ratio (m/z) and in which the deflection and intensity of the beams are recorded directly on a photographic plate or film. 

A transition step between the reaction system just considered (silver ions, p-phenylenediamine, silver sol) and actual physical development of a fixed photographic plate or film is supplied by the investigations of Arens (27, 28). He used a series of silver, gold, and silver sulfide sols which had been coated on glass plates, using gelatin as the binding material. In this way he obtained plates in which colloidal particles... 

Note "Photographic or Cinematographic Goods" refers to HS (Harmonized Commodity Description and Coding System) Code 37. Products in this classification include "photo plates and film, flat, sensitized, unexposed photo film in rolls sensitized, unexposed photo paper, paperboard and textiles, sens, unexposed photo plates, film, paper, etc, exposed, not developed photo plates and still film, exposed developed motion-picture film, exposed and developed photographic chemicals, unmixed products retail packed."... 

Historically, several types of electrical excitation sources have been used since the early part of the 1900s, among them the DC arc, the AC arc, and the AC spark. Commercial instmments using electrical excitation sources became available about 1940 with PMT detectors prior to this, emission instruments used a photographic plate or film as the detector. Modern instruments are either DC arc emission instruments or high voltage spark... 

The contrast (y) of a photographic emulsion also is dependent on wavelength, where the contrast generally increases as the wavelength increases. A calibration curve for an emulsion, therefore, is only correct at the particular wavelength at which it was obtained. Spectral sensitivity curves for some commonly used spectral plates and films are shown in Figure 6-8. 

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