Dark room procedure

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DARK ROOM

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D E P T T. O F R A D I O D I A G N O S I S & I M A G I N G
M G H J A I P U R
DARK ROOM

3. INTRODUCTION
A dark room is very important place in the radio
diagnosis department where radiographic
processing takes place and so called
processing room. Here, we also perform
loading and unloading of film inside the
cassette.
The name given “Dark Room” is because it is
made dark while processing, means we use
no white light at that time.
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4. DARKROOM

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 Ideally the dark room should always be located
centrally in the department for efficient working.
 In addition, the dark room should also be located
close to the radiographic room, if possible next to
the radiographic room sharing a common wall. As it
saves lot of time .
 Dark room should also be located away from damp
and hot areas.
 It should be located in the place accessible it terms
of power and water supply.
LOCATION

6. SIZE AND INSTALLATION OF THE
DARKROOM
 A darkroom must be large enough (ideal is 100
square feet floor and 11 feet ceiling height) to
accommodate all the necessary equipment
without overcrowding.This equipment
comprises the loading bench and the processing
tanks, each with the requisite accessories. It is
essential for dry and wet work to be carried out
at a safe distance from each other ;for this
reason the loading bench and processing tanks
are arranged along opposite side of the room
,referred to as the ‘dry’ and ‘wet’ sides.
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7.  A. PROTECTION AGAINTS RADIATION
BUILDING ESSENTIALS
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 It is essential for the darkroom to be well protected
against radiation.The lead equivalence of the wall
adjoining the radiographic room should be efficient
to prevent the films from fogging.
 The wall should be lined with lead sheet or some
substance of 1.5-2 mm thickness of lead or lead
equivalent to work under 100-150 KV.

8. B. FLOOR
 The floor should be durable
 Easily cleaned
 Not slippery & Resistant to staining
 Ceramic tiles of porcelain or natural clay are
the most satisfactory.
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C . Wall Covering
 Walls of the darkroom do not have to be dark.The
color chosen should first be judged under safelight
illumination as it is important that there should be
maximum reflection of safelight . eg. Pink, cream
and white
 The walls should be covered with chemical –
resistant materials such as special paints ,varnish ,
concrete or ceramic tiles

10. VENTILATION
Sufficient ventilation is necessary to avoid
excessive exposure to chemical vapors
which can cause respiratory diseases .
• Temp/Humidity should be maintained at
optimum level to prevent static electricity
& temp. fog.
• Window should be avoided because they
are difficult to render lightproof.
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CONT’D………..
•Air conditioner is an ideal solution for the dark
room ventilation which control the
temperature as well as humidity of the
darkroom.
The temperature of darkroom should be 18-20
degree and humidity should be 40-60%.

12. ELECTRIC WIRING
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The dark room is a place where electric shock can
be dangerous.
Because of the presence of electric wiring in the
proximity of aqueous solutions , water pipes ,
damp floors and wet fingers.
It is essential to earth all exposed non-current
carrying metallic objects.

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 The simple type of entrance is a single door which
must be made light tight and should have an inside
lock to prevent opening while films are being
processed.
 Another type of entrance is a small hall with two
electrically doors , so designed that one door can
not be opened until the other is completely closed ,
thereby preventing entrance of light.
 Another type of door is labyrinth door. This type of
door consists of two parallel passages and a facing
wall.
ENTRANCE
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The preferred entrance these days is revolving
door which occupies very little space and offers
convenient , lightproof acess to the dark room.
Cont’d………..
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15. DARKROOM ENTRANCE:
SINGLE DOOR

16. DARKROOM ENTRANCE:
DOUBLE DOOR

17. DARKROOM ENTRANCE:
MAZE

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DARKROOM ENTRANCE: REVOLVING
DOOR

19. .SAFE LIGHT
.GENERAL ILLUMINATION
.WET
. DRY
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ILLUMINATION
•BENCHES
DOOR
TYPE,REVOLVING
PASS BOX
COMPONENTS OF DARKROOM

20. DARKROOM COMPONENTS

21. PASS BOX
 The most suitable location for the pass box is
near the film loading bench .Typical pass box
has two light tight and x-ray proof doors that
are so interlocked that both cannot be
opened at the same time .The pass box is
divided into two compartments , one for
exposed and the other for unexposed film.
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Door type Rotating 22
PASSBOX

23. ILLUMINATION
The dark room should have two types of
illumination.
1.Safe light
The dark room should have a source which will
not fog films and also provide adequate
illumination. Safelight lamp serve this
purpose; they should have a filters of the
proper colour.
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24. Cont’d……………..
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•Bulb size /location :
•For 7Watt -3 feet
• GBX-2
•For 15Watt – 4 feet from work surface.
•FILTRS – varies with types of film :
Kodak Wratten 6B-(orange brown light)blue violet sensitive;
Kodak GBX-(deep red light)yellow green sensitive

25. Safelights; Direct and indirect
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26. FILMTRAY
7.5W
AT LEAST 3 FEET FROM THE FILM
TRAY

27. FILMTRAY
15 W
AT LEAST 4 FEET FROM THE FILM
TRAY

28. 2.General illumination
*A source of overhead lighting is needed for general
purpose such as cleaning , changing solutions etc.
*General white light bulb is used for this. We turn it
on during all the time except while processing film.
** An important thing to note is that the switch for
this light should be separated, preferably higher
than the switch of safe light

29. Dry Benches
A long table should be used for loading
/unloading cassettes.
This bench is considered to be dry because no
chemicals are put here.
Dimensions
At least 2.5cm in length and 60 cm width and
height should not be less then 90 cm.
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30. Wet Benches
It is the side where we keep processing
chemicals.
There are shallow tanks filled with developer,
water for rinsing , fixing and washing
respectively for manual processing.
Now a days auto processor are in use. Auto
processor is also put in the wet bench.
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1
• DeveloperTank
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• RinsingTank
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• FixerTank
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• WashingTank
Manual ProcessingWet Bench

32. AUTOMATIC PROCESSORS WET BENCH

33. • For manual processing, films are clipped to
some type of film hangers .
•The film should be handled only by the edges
to avoid damage.
•The film hanger, with films attached, is then
placed in the processing solutions, developer
first.
•The films are hung with the help of these
Hangers in the drying area for drying.
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Film Hangers

34. Hangers Clip type

35. CONCLUSION
 Dark room is very important for radio
diagnosis department because it plays a vital
role in processing of film.
 To obtain a good quality radiograph we have
to have a good conditioned darkroom with
fulfillments of all the necessary components.
 Any fault in darkroom layout and
construction may result in degrade of
radiographic quality and also may harm the
person working in the darkroom.
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REFERENCES:

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