P2: PPT (PROCESSING OF LATENT IMAGE - AUTOMATIC PROCESSING)

Automatic Processing

Principal Components of _____

1. Transport system
2. Temperature control system
3. Circulation system
4. Replenishment system

Transport

Principal Component of an Automatic Processor

System: ____

Purpose:
Transports film through various stages at precise intervals

Rollers

Principal Component of an Automatic Processor

System: Transport

Subsystem: ____

Purpose:
Supports film movement

Transport Racks

Principal Component of an Automatic Processor

System: Transport

Subsystem: ____

Purpose: Moves and changes direction of film via rollers at a precise rate

Drive

Principal Component of an Automatic Processor

System: Transport

Subsystem: ____

Purpose: Provide power to turn rollers at a precise rate

Temperature Control

Principal Component of an Automatic Processor

System: _____

Purpose:
Monitors and adjusts temperature at each stage

Circulation

Principal Component of an Automatic Processor

System: ____

Purpose:
Agitates fluids

Developer

Principal Component of an Automatic Processor

System: Circulation

Subsystem: ____

Purpose:
Continuously mixes, filters

Fixer

Principal Component of an Automatic Processor

System: Circulation

Subsystem: ____

Purpose:
Continuously mixes

Wash

Principal Component of an Automatic Processor

System: Circulation

Subsystem: ___

Purpose:
Single-pass water flows at constant rate

Developer

Principal Component of an Automatic Processor

System: Replenishment

Subsystem: ____

Purpose:
Meters and replaces

Fixer

Principal Component of an Automatic Processor

System: Replenishment

Subsystem: ____

Purpose:
Meters and replaces

Dryer

Principal Component of an Automatic Processor

System: ____

Purpose: Removes moisture, vent exhaust

Transport System

Principal Component of an Automatic Processor

Begins with feed tray (where film to be processed is inserted) and grip by the entrance rollers and transfer to the wet chemistry

Feed Tray

Principal Component of an Automatic Processor: Transport System

where film to be processed is inserted

Shorter

Principal Component of an Automatic Processor: Transport System

The ___ dimension of the film should always be against the side rail, so the proper replenishment rate is maintained.

Film to Film

Principal Component of an Automatic Processor: Transport System

Feed alternate side from _____ to ensure even wear of the transport system component.

Transport System

Principal Component of an Automatic Processor

Functions:
• transport the film in the automatic processor at a constant speed.

• control the film immersion time in the wet chemicals.

Principal Subsystem
a. Rollers
b. Transport racks
c. Drive motor

Rollers

Principal Component of an Automatic Processor: Transport System

Principal Subsystem - ___

Types:
1. Transport
2. Master
3. Planetary

Transport Rollers

Type of Rollers

1 inch diameter. Conveys the film along its path. Positioned opposite one another in pairs or are offset from one another.

Master Rollers

Type of Rollers

- a.k.a. Sun rollers or Solar Rollers
- 3 inches diameter. Use when the film is turn in the processor.

Planetary Rollers

Type of Rollers

- 1 inch diameter. Rollers position around the master rollers. Together with master roller and guide shoes, it guide to reverse the direction of film in the processor

Guide Shoes

Type of Rollers

A master roller with planetary rollers and ____ is used to reverse the direction of film in the processor

Transport Racks

Principal Component of an Automatic Processor: Transport System

Principal Subsystem - ___
1. Guide shoes
2. Crossover rack

Guide Shoes

Type of Transport Racks

- a curve metal lip with smooth grooves that guides the film around the bend.

Crossover Rack

Type of Transport Racks

smaller rack that composed of rollers and guide shoes. Guides the film to adjacent rack assembly/tank

Drive

Principal Component of an Automatic Processor: Transport System

Principal Subsystem - ___

• ___ motor controls the speed of the film transport or the film immersion time.

• The shaft of the ___ motor is usually 10-20 rpm.

Thermocouple or Thermistor

Principal Component of an Automatic Processor: Temperature Control System

monitor the temperature of each processing stage.

35

Principal Component of an Automatic Processor: Temperature Control System

Developer temp should be maintained at __ °C Developer temp is most critical

3

Principal Component of an Automatic Processor: Temperature Control System

Wash water is maintained __ °C below developer temp

Temperature

Principal Component of an Automatic Processor: Temperature Control System

is controlled thermostatically by heating element in each tank.

Transport System

Principal Component of an Automatic Processor: Temperature Control System

____ also helps maintain the temperature.

Circulation System

Principal Component of an Automatic Processor

- It provides continuous mixing of chemicals
- It continuously pumps the developer and fixer in automatic processor.

Agitation

Principal Component of an Automatic Processor: Circulation System

____ of the chemicals also helps to maintain constant temperature and strength of the chemicals.

Filters

Principal Component of an Automatic Processor: Circulation System

are required in the developer circulation system to traps small particles (e.g. gelatin) that may attached in the rollers that can produce artifacts.

Fixer

Principal Component of an Automatic Processor: Circulation System

Filters in the fixer circulation system is not necessary because the ____ hardens and shrinks the gelatin.

12

Principal Component of an Automatic Processor: Circulation System

For wash tank, open circulation system is preferred (min. flow rate of __ L/min ). Fresh tap water is piped into the tank at the bottom and overflows out the top.

Replenishment System

Principal Component of an Automatic Processor

• Its function is to add solution to the developer and fixer as each piece of x-ray films moves through the system.

• It contains pump controlled by microswitch.

• It compensate the loss of chemical activity
and volume loss

Microswitch

Principal Component of an Automatic Processor: Replenishment System

It contains pump controlled by ___

Chemical Activity

Principal Component of an Automatic Processor: Replenishment System

Loss of _____:
a. Direct oxidation
b. Aerial oxidation
c. Contamination

Volume

Principal Component of an Automatic Processor: Replenishment System

Loss of ____:
a. Air evaporation
b. Carry-over

Developer

Principal Component of an Automatic Processor: Replenishment System

Replenishment Rate
60-70 mL of ___ per 35 cm (14") of film

Fixer

Principal Component of an Automatic Processor: Replenishment System

Replenishment Rate
100-110 mL of ____ per 35 cm (14") of film

Less

Principal Component of an Automatic Processor: Replenishment System

*As a general rule, the more films that are processed per day, the ____ the amount of chemicals that need to be replaced; and vice versa.

Overreplenishment

Principal Component of an Automatic Processor: Replenishment System

causes slight increase in contrast and density.

Underreplenishment

Principal Component of an Automatic Processor: Replenishment System

causes reduce film speed, contrast and density

Measuring Replenishment Rate

Principal Component of an Automatic Processor: Replenishment System

What do you call this?

*Disconnect the replenishment line at its high point in the processor and catch the chemistry in the graduated cylinder while a 14" film is being fed.

Time

Principal Component of an Automatic Processor: Replenishment System

The duration of the replenishment is determined by the length of ____ it takes for a film to enter the system.

Microswitch

Principal Component of an Automatic Processor: Replenishment System

Once the film is completely in the transport system and in the developer tank, the ___ stops the operation of the replenishment pump.

Replenishment Tank

Principal Component of an Automatic Processor: Replenishment System

• Outside the processor
• Chemistry should be replaced every approx. 2 wks
• Should have a floating lid and dust cover to reduce loss of activity due to aerial oxidation

Dryer System

Principal Component of an Automatic Processor

Removes residual moisture from the processed radiograph.

Consist of blowers, ventilation ducts, drying tubes, and exhaust system.

2500

Principal Component of an Automatic Processor: Dryer System

A blower draws in room air and blows it across heating coils (____ W) through ductworks to the drying tubes.

110 to 120

Principal Component of an Automatic Processor: Dryer System

Air temperature of the dryer is between approx. ____ °F (43-49 °C)

Damp Films

Principal Component of an Automatic Processor: Dryer System

Common causes of a ____:

1. Malfunctioning dryer system
2. Chemical failure (may be caused by contamination, lack of hardener due to underreplenishment)

Chemical Failure

Principal Component of an Automatic Processor: Dryer System

Common cause of a damp films: _____ may be caused by contamination, lack of hardener due to underreplenishment

Maintaining the Processing Unit

What do you call these?

Maintenance procedures include:

1. Routine checks and clean of transport rollers.
2. Careful examination and adjustment of guide shoes.
3. Cleaning and replacement of filters throughout the processor unit.

Sludge

Maintaining the Processing Unit

Maintenance procedures include:
1. Routine checks and clean of transport rollers.
• ___ can build up on the rollers that may cause artifacts (pi lines artifacts)
• Crossover racks should be washed daily

Artifact

Maintenance procedures include:

2. Careful examination and adjustment of guide
shoes.
• Improper position or springing of guide shoes in turnaround assembly will cause ___ (guide shoe marks)

Filters

Maintenance procedures include:

3. Cleaning and replacement of filters throughout the processor unit.
• ___ traps small particles that have a chance of becoming attached to the rollers/film and causes artifacts

Daylight Processing System

Processing of film without the need for a conventional darkroom.

Daylight Processor

Daylight Processing System

Attached to the film processing unit is a ___, a mechanical film loader.

Mechanical System

Daylight Processing System

____ removes the exposed film in the cassette and stated the processing cycle. The cassette is then loaded load with an unexposed film stored inside the daylight processor storage magazine

Daylight Processing System

Advantages

1. Eliminates the need of darkroom
2. Eliminates the need to train personnel

Daylight Processing System

Disadvantages

1. More costly than the standard automatic processor
2. Mechanical breakdown may occur
3. Artifact caused by mechanical devices that moves the film through the system

Silver

• is a valuable substance
• is also a polluting agent

Silver Recovery

• ____ from the fixer solution makes it available for recycling.

Silver Recovery

Method in Recovering Silver

1. Chemical recovery unit
2. Electrolytic recovery unit

Chemical Recovery Unit

Methods in Recovering Silver

Chemical Method
a. Precipitation of the silver
b. Replacement of the silver by another metal

Precipitation of the Silver

Methods in Recovering Silver: Chemical Recovery Unit (Chemical Method)

• Adding sodium sulfide to the fixer solution results in precipitated silver sulfide.
• (sodium sulfide + silver bromide = silver sulfide precipitate)

Precipitation of the Silver

Methods in Recovering Silver: Chemical Recovery Unit (Chemical Method)

• This method is highly efficient but the disadvantages are production of toxic fumes and difficulty of handling and drying silver sulfide sludge.

Replacement of the silver by another metal

Methods in Recovering Silver: Chemical Recovery Unit (Chemical Method)

• Use of some metal (e.g steel wool) to replace the silver.

• Iron ions of the steel wool will go into the solution, and the silver in the solution will plate out on the steel
wool

Re-use

Methods in Recovering Silver: Chemical Recovery Unit (Chemical Method)

The chemical methods of silver recovery makes the fixer unsuitable for ____ in the processing of the film.

Electrolytic Recovery Unit

Methods in Recovering Silver

a.k.a electrolysis

• It is the process of producing a chemical change by passing an electrical current through an ionized solution.

• Its advantages are high efficiency in recovering silver and it allow the fixer to be re-used.

Electrolytic Recovery Unit

Methods in Recovering Silver

• Its advantages are high efficiency in recovering silver and it allow the fixer to be re-used.

Electrodes

Methods in Recovering Silver: Electrolytic Recovery Unit

The electrolytic method uses 2 ____: the canister containing the anode (+), usually made of carbon, and the cathode (-), usually made of stainless steel.

Silver Ion

Methods in Recovering Silver: Electrolytic Recovery Unit

• As the fixer solution passes through the canister, the ____ (Ag+) are repelled by the canister and attracted to the cathode and will be plated on the stainless steel.

• The cathode structure must be removed frequently to "chipped" off the silver.