Darkroom and Film Processing

1
Darkroom and Film Processing

• Rad Tech A Week 8Fall 2005

2
Darkroom
3
Darkroom
4
Darkrooms Still Necessary?

• Darkrooms are necessary for manually fed
  processors and daylight processors.
• -Loading automatic film processor magazines.
• Necessary for conducting certain quality control
  tests (daily sensitometric strip).

5
Darkrooms 4 Basic Functions

• Number 1 Function
• Storage
• Unexposed film

6
Film Bin
7
(No Transcript)
8
(No Transcript)
9
DARKROOM FUNCTION 2

• Purpose of Film Processing
• Change silver halide crystals from film emulsion
  (after exposure to x-ray or light photons) to
  black metallic silver.
• Latent image (invisible until processed) is
  developed into a Manifest image.
• Improper or careless processing can cause poor
  diagnostic quality.

10
Manual Feed Processor
11
Processing Film
12
TABLE TOP PROCESSOR
13
(No Transcript)
14
WILL THIS WORK ????
15
Daylight Processor
16
Function 3 Handling of Film
17
UNLOAD EXPOSED FILM
18
Basic Recommendations

• Follow mfg. recommendations
• -strength of chemicals
• -temperature of chemicals
• -time requirements in each chemical
• Solutions should be replenished as necessary
  changed regularly
• Solutions must be monitored (Daily QC strip).

19
Function 4 Film Identification

• Pt name
• Exam date time
• Pt x-ray number
• Pt Birthday/DOB
• Rt or Lt marker
• Optional
• Exam type
• Dr. Name

20
FILM ID PRINTER
21
AUTOMATIC PROCESSING

• TRANSPORTATION SYSTEM
• DEVELOPER
• FIXER

• WASHER
• DRYER
• REPLENISHMENT SYSTEM

22
Automatic Processor
23
Processor Chemistry Overview

• Developer converts latent image into manifest
  image
• Fixer clear the film of unexposed, undeveloped
  silver bromide crystals, promotes archival
  quality
• Wash rid the film of residual chemicals

24
Developer Solution(6 Ingredients)

• Reducing Agent reduce exposed silver halide to
  black metallic silver
• -Hydroquinone (Blacks)
• -Metol or Elon
• -Phenidone (Grays)
• 2. Activator softens gelatin, maintains
  alkaline pH (increase pH)
• -Sodium Carbonate

25
Developer Solution

• 3. Hardener prevents damage to the film from
  over swelling of gelatin in automatic processors.
• -Gluteraldehyde
• 4. Preservative Antioxidant that prevents
  oxidation of developer
• -Sodium Sulfite

26
Developer Solution

• 5. Restrainer prevents chemical fog in new
  developer
• -Potassium Bromide
• 6. Solvent dissolves ionizes the developer
  chemicals
• -Water

27
Fixer Solution(5 Ingredients)

• Clearing Agent dissolves undeveloped silver
  halide
• -Ammonium Thiosulfate
• 2. Tanning Agent shrinks, hardens, preserves
  emulsion
• -Aluminum Salt

28
Fixer Solution

• 3. Activator neutralizes developer, maintains
  acidic pH (decrease pH)
• -Acetic Acid
• 4. Preservative prevents oxidation, prolongs
  solution life
• -Sodium Sulfite
• 5. Solvent dissolves other ingredients
• -Water

29
Wash

• Rid the film of residual chemicals
• Residual chemicals on the film will discolor
  radiograph over time.
• Cold water processors are less efficient in
  removing chemicals Warm water processors much
  better.
• Agitation during wash process is essential

30
Fixer Retention(Not Washed Off)
31
Transport System Components

• Feed Tray
• Rollers (Different Assemblies)
• 1. Entrance
• 2. Deep Racks
• 3. Turnaround
• 4. Crossover
• 5. Squeegee
• 6. Dryer
• Receiving Bin

32
Transport System (Rollers)
Entrance
Crossover
Feed Tray
Squeegee
Deep Racks
Dryer
Turnaround
33
Processor (Top View)
34
Replenishment System

• Main function Keep solution tanks full and
  assure proper solution concentration.
• As film is introduced into processor, sensor
  initiates solution replenishment
• Right wrong way to feed in film
• -Feed in along short edge

35
Transport System in Automatic Processors

• Conveys the film through different solutions
  (sections) by a series of rollers driven by
  gears, chains sprockets.
• Done at a prescribed speed determines length of
  time the film is in each solution

36
Temperature Regulation

• Main function To control the temperature of each
  section of the processor.
• Developer most important solution to regulate
• Usually between 92 degrees and 95 degrees
• Thermostatically controlled

37
Recirculation System

• Provides agitation necessary for uniform solution
  concentration

38
Wash Dryer Systems

• Wash Provide thorough removal of chemical
  solutions from the film.
• -Archival film quality
• Dryer Removes water from film by blowing warm,
  dry air
• -Between 120 degrees 130 degrees F.

39
Silver Recovery

• About ½ of the films silver remains in the
  emulsion after exposure processing.
• Other ½ (unexposed silver) is removed from the
  film during fixing process.
• Silver is toxic to public water supply must
  have proper disposal.

40
What is in the Darkroom?
41
(No Transcript)
42
Darkroom Equipment
43
Darkroom Equipment
44
Safe Light

• 15 Watts
• Red filter
• Must be 3-6 feet from counter top or feed tray of
  processor
• Used to be amber or orange filter

45
Darkroom Summary
46
Darkroom Contents

• Loading Bench
• Film Bin
• Film I.D. Printer
• Safelights
• Pass Box
• Light-tight Room
• Ample ventilation

• Warning Light outside room
• Lockable Door
• Wall Shielding if adjacent to x-ray room
• Walls painted with light color to reflect
  safelight

47
Summary Questions
48
RTA LAB 2 PROCESSING SCREEN EXPOSURE

• IONIZING LAB
• INTENSIFYING SCREEN
• DARKROOM
• PROCESSING CHEMISTRY
• COMPLETE IN CLASS WORKSHEET