- Term “darkroom” overstates the case
- White light is EXCLUDED.
- Important place in the radiology department of a hospital, clinic, nursing home or a private x-ray clinic.
- Is a room where the latent image is processed into visible image by means of chemical processing. Hence also called processing room.
BASIC FUNCTION OF DARK ROOM
• Storage – of unexposed films
• Film processing
• Handling of films
•Loading and unloading the film
- Centrally located
- Close to radiographic room- time saving
- Away from hot, damp basement areas.
- Serviced by hatches from the adjacent imaging room
- Accessible in terms of water and power supply
- Adjoining viewing room
2. SIZE & INSTALLATION
- Large enough to accommodate all necessary equipments without crowding.
- Parameters of an ideal dark room-
- floor space- 100 sq.feet
- Ceiling height- 11 feet
- Size can vary depending on the department needs.
- Safe distance between dry and wet side.
- Loading bench and processing tank on opposite sides.
3. BUILDING ESSENTIAL
3.1. PROTECTION AGAINST RADIATION
- Essential-to prevent film fogging
- Walls being lined by- lead sheet or lead equivalent material
- 1.5 mm or 1.6 mm lead mostly used.
- Alternative- solid concrete wall construction- 15cm thick
- It leads to sufficient work upto 100kV.
- non- porous
- non- slippery
- chemical resistant
- stain proof
- durable & easy maintenance
- Light colored
- satisfactory material-
- ceramic tiles of porcelain
- natural clay
- Asphalt tiles
- unsuitable materials- ordinary linoleum and concrete.
- do NOT have to be dark.
- color judged under safe light illumination- ensure maximum
- reflection into working surface.
- covering with chemical resistant materials-special paint, varnish, concrete or ceramic tiles
- easy to wipe/clean
- Window avoided
- Relative humidity maintained- 40-60%,room temp- 18-20 degree Celsius.
- Ideal solution- good air conditioning system
- Alternative –extractor fan- creates positive air pressure.
5. ELECTRICAL WIRING
- Electric shock is dangerous- as close proximity with
- chemical tanks
- Water pipes
- Damp floors
- Wet fingers
- Prevention- proper earthing .
6. PASS BOX
- Designed – to transfer film cassettes to and from the dark room without radiation light entering.
- Include 2 compartments-
- Metallic structures with lead lining- x-ray shielding
- Typically wall mounted
- Near film loading bench
- Include x-ray proof automatic interlocks, closes one door when other is opened.
- provides temporary storage of loaded cassettes.
•There are following types of entrance used in dark rooms-
A. Single door-
- simplest type of entrance
- Single door- light tight & radiation proof
- An inside lock
B. DOUBLE DOOR
- having 2 doors
- one leading IN
- other used for OUT
c. MAZE TYPE
- elaborate type of entrance
- NO requirement of door
- serves as a light trap
- High cost
- Large space occupying
- Rarely used these days.
D. REVOLVING DOOR
- Occupies very little space
- convenient light proof access to dark room
- echo- friendly
- The dark room should have 2 types of illumination-
- general illumination/white lighting
- safe light/radiographic illumination
- Inspection & maintenance of cassette and screen
- Cleaning of work space
- Servicing of equipment
- Sited close to ceiling- avoids strong shadow
- Moderate in intensity
- Centrally placed
- More than one switch preferable
- Identification of such switches is important
direct – distance: 1.2m from working surface
indirect- distance: 2.1m from floor
- Provide adequate illumination without fogging films.
- Have filters of proper colors(red filters can be used for both blue and green sensitive films) •
- Working distance- not less than 1.2 m.
- Bulb wattage- d less than 15 watts. I – 25 watt
- Work quick under it.
- Not completely safe, prolonged exposure- fogging of films
9. DRY SIDE
•Components comprises of-
- Loading bench
- Compartment for cassettes
- Film bin
- Storage for reserve film
- Brackets for film hangers
- Wastepaper receptacle
10. WET SIDE
- Processing tank-simplest type has 4 compartments- • 1. developing 2. rinsing 3. fixing 4.washing tank
- stainless steel of alloy- generally used material.
- Processing chemicals
- 2 stirring paddlers
- Washing tank
11. FIRE SAFETY
- Ideally all darkrooms should be provided with fire exits
- Clearly indicated
- Left unobstructed at all the times
HAVE A NICE DAY & DROP A COMMENT BELOW
YOU CAN REQUEST A TOPIC ON MAIL AND AS WELL AS IN A COMMENT BOX
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