Darkroom Illumination: - dividend into 2 ordinary white light and safe light.
White light is important because of the following
• To inspect and maintain cassette and screens
• Cleaning of all work surfaces and floors
• And to services the processors
Sitting of the white light
* Sited close to the ceiling (to avoid casting strong shadow)
* Moderate in intensity (60W tungsten or 30W fluorescent) (accommodation easier after safe light)
* Centrally place or otherwise
All films get fogged when exposed by the white light
Safe Light
A safe light is a red light bulb situated in a darkroom at a distance of 1.2m (4 ft) off the working surface and use for a processing purpose.
And a colored lighting which provides sufficient illumination by which one can handle, manipulate and process film with no significant fogging occurring,
These ensure loading and unloading of x-ray cassette much easier and provides pleasant working condition for the personal.
No safe light is completely safe; - because all films comes significantly fogged when exposed to safe light for long time.
Majorly due to safe light filter are not perfect absorbers of the undesirable wavelength and all films have some sensitivity to all wavelength, The intensity illumination and film handling time must be kept to a minimum in other to avert fogging.
Safety Film Handling
From moment a film removed from the cassette to the time it disappears inside the processor make sure is only exposed to safe light,
Always take a film with clean and a dry hand and only touch it at the corner do not crack the film.
Types of safe light
• Direct safe light
• Indirect safe light
Direct safe light: - this method allows light from the safe lamp to fall directly on the work surface, it’s illumination should be sited at a distance of 1.2m (4 ft) off the working surface, usually the best type of light for film loading and unloading areas.
Indirect safe light is intended to provide general illumination of the darkroom. The safe lamp is directly toward the ceiling (brightly painted) to reflect light back into the room.
The Cassette Hatch: - it allows easy transport of film and cassette between exposure room to darkroom, The hatch door that opens to the x-ray room is 2mm thick lead lined while the opposite door opens into the darkroom. It has features:
1 Interlocking device; which prevents both door to be opened simultaneously and allowing light through
2 Partition and labelled exposed for exposed cassette and unexposed for freshly loaded cassette.
Film Hopper: - are used to store temporary films for immediate use and located under the loading bench, the hopper should be
• Light tight
• Micro switch
Reference
Fadila and Comr. Muazu, MIT Abdussalam A. Madaki (2019 — 2022) Students’ manual for the processing of Radiographic films. Madaki and Mohammad Moses technical research Nigeria.
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