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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 |