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Processing Chemicals
Question | Answer |
---|---|
What is the reducing agent in the developer? | hydroquinone and phenidone |
Which reducing agent in the developer produces black and white? | hydroquinone |
Which reducing agent in the developer produces grays? | phenidone |
Name the activator in the developer that swells the gelatin and makes an alkaline pH? | sodium carbonate |
Potassium Bromide | starter/antifoggant/restrainer in the developer; it decreases the activities of fresh chemicals |
This preservative is a buffer that preserves original concentration of the chemicals? | sodium sulfite |
Hardens the emulsion in the developer | gluteraldehyde |
Solvent used in both the developer and fixer? | water - dissolves the chemicals |
What are the four steps in film processing? | developer, fixer, washing, dryer |
What is the total time of the film processing? | 90 seconds |
What is the cleaning agent in the fixer? | Hypoammonium thiosulfate |
What is the purpose of the cleaning agent in the fixer? | It removes silver halide crystals that were undeveloped and stops reduction |
Acetic acid | activator found in the fixer and makes the acid pH and stops reduction |
Gluteraldehyde is the hardener found in the fixer that hardens the emulsion. T/F | False - Potassium alum is the hardner in the fixer |
What preservative is found in both the fixer and the developer? | sodium sulfite |
What is the purpose of the replenishment tanks? | refills the developer and fixer tanks; 100-110 ml per 14" of film |
What is the silver recovery unit? | mechanism to collect the silver |
When is the image manifest? | In the developer due to hydroquinone (blacks and whites) and phenidone (produces grays) |
It there is an ammonia smell what has happened? | mixture of chemicals |
What is the purpose of the crossover rollers? | takes film from one tank to another |
Scwegie rollers | takes excess chemicals off of film to prevent contamination |
Purpose of splash guards. | prevent splashing and mixture of chemicals |
What is the purpose of the silver recovery units? | economical and ecological |
What are the two types of silver recovery units? | electrolytic and chemical |
Aggitation upon imersion helps to produce ________. | uniform development |
Why is the water kept at 5-7 degrees lower than the temp of the chemicals? | To stabilize the developer |
Two purposes of the circulation system. | provides agitation and helps to mix the chemicals |