title: [The influence of the spectrum and the type of exposure on the contrast of double-sided coated x-ray film].
abstract: The present article describes the circumstances concerning the use of testing aids such as sensitometers with one-sided exposure. It is shown which phenomena must be considered if radiographic films coated on both sides are exposed with a) standard pocket sensitometers (one-sided exposure), b) lab sensitometers (double-sided exposure to ANSI Ph 2.9 [1964]), c) x-radiation in the cassette, intensifying screen and film system (to DIN 6867 T 1). The effect of the emission spectrum on the resulting contrast factor is described. The importance of different emulsion technologies (e.g. orthochromatic anticross-over films) for the contrast factor with one-sided exposure is described. The cross-over factor (c.o.), the apparent variation in sensitivity of the front and back emulsion with one-sided exposure, is the cause of the reduction in the contrast factor (G average) as against double-sided exposure: delta G(%) = c.o.2 x 10(3)/8.4
authors.affiliation: Agfa-Gevaert AG, Leverkusen.
authors.forename: C
authors.initials: C
authors.lastname: Blendl
authors.forename: R
authors.initials: R
authors.lastname: Bollen
authors.forename: K H
authors.initials: KH
authors.lastname: Freytag
mesh_terms: D008029:Lighting; D013052:Spectrometry, X-Ray Emission; D013679:Technology, Radiologic; D014962:X-Ray Film / Q000592:standards*
vernacular_title: Der Einfluss des Spektrums und die Art der Belichtung auf den Kontrast doppelseitig beschichteter Röntgenfilme.