The ease with which Biomax-MS can be used in place of DEF (same format film, same developing process, and comparable sensitivity) makes it a good replacement. The lower exposure results from thinner emulsion layers, designed for use with phosphor screens. (cross-section) (A), Bakelite plastic front faces tube (B), front intensifying screen with crystals facing film (C), x-ray (D), back intensifying screen with crystals facing film (E), felt cushion (F), lead foil backing (G), hinged metal back (H) metal frame for support.= 50%). Cassette with the film in place between the built-in intensifying screens. The cassette must also be loaded in the darkroom.įigure 2-9. The lead foil backing in a cassette helps prevent fogging as it does in the cardboard holder. One screen is mounted on the inside of the lid and the other on the inside of the Bakelite front of the cassette. It is used with two intensifying screens, one on either side of the film (figure 2-9). A cassette is a film holder about 1/2-inch thick with a metal frame (either aluminum or stainless steel), a front of Bakelite, and a hinged lid with flat springs. This lining helps prevent fogging from backscatter radiation.ī. The front of the holder must face the x-ray tube during an exposure, since there is a lead foil lining in the back. They have lightproof envelopes in which the film is placed before being taken from the darkroom. These holders are made to fit the various film sizes. For DC, capacitor discharge and 3-phase x-ray, the 8700 measures the exposure time in milliseconds. Pulses produced by half-wave and full-wave x-ray are measured as 60 or 120 pulses per second.

The RVG-S permitted dose reductions of 50 to 65 for individual exposures in comparison with Ektaspeed film, and 73 to 76 when. of a photographic film to light is equal to the product of the intensity of the light and the duration of the. The exposure required to obtain optimal image quality was determined using conventional intraoral x-ray film (Eastman Kodak, Rochester, NY) and the RVG-S Radio VisioGraphy-S: Trophy Radiology, Vincennes, France) CCD-based intraoral radiographic imaging system. In order to increase radiographic film density by 40, the radiographer would: a. The direct-exposure film holder (cardboard holder) meets both of these requirements. The x-ray sensor in the 8700 allows direct measurement of exposure from the x-ray head. The factors that affect x-ray emission under the direct control of the radiographer are called the factors. Patient exposure can be reduced by up to 100 times when compared to direct exposure film techniques. This feature enables image formation to occur with less exposure than is possible with direct x-rays alone. They must (1) protect the film from light, and (2) allow the film to be exposed to x-rays.Ī. screens that convert x-ray energy to light energy. Holders for x-ray film must have two characteristics.

Direct exposure x-ray film