Time Temperature Chart | |||
Thermometer Readings (Degrees) | Minimum Developing Times (Minutes) | ||
C | F | ||
27 | - | 80 | 2 |
79 | 2 | ||
78 | 2 ½ | ||
77 | 2 ½ | ||
24 | - | 76 | 3 |
75 | 3 | ||
74 | 3 ½ | ||
73 | 3 ½ | ||
22 | - | 72 | 4 |
71 | 4 | ||
70 | 4 ½ | ||
69 | 4 ½ | ||
20 | - | 68 | 5 |
67 | 5 ½ | ||
66 | 5 ½ | ||
65 | 6 | ||
18 | - | 64 | 6 ½ |
63 | 7 | ||
62 | 8 | ||
61 | 8 ½ | ||
16 | - | 60 | 9 ½ |
Processing of Film
1. Manual processing of film.
a. Where film is developed manually, processing tanks should be made of mechanically rigid, corrosion resistant material and the temperature of solutions in the tanks shall be maintained within the range of sixteen degrees Celsius to twenty-seven degrees Celsius [60-80 degrees Fahrenheit]. Film shall be developed in accordance with the time-temperature relationships recommended by the film manufacturer, or, in the absence of such recommendations, with the above time-temperature chart.
b. Devices shall be available which will give all of the following:
(1) The actual temperature of the developer.
(2) An audible or visible signal, after a preset time (in minutes of duration).
2. Automatic processors and other closed processing systems.
a. Film shall be developed in accordance with the time-temperature relationships recommended by the film manufacturer.
b. The specified developer temperature and immersion time shall be posted in the darkroom or on the automatic processor.
c. Preventive maintenance shall be performed on the unit, except for extended periods of nonuse, on a frequency basis which is not less than that schedule recommended by the manufacturer. In the event that no schedule is available from the manufacturer a maintenance schedule shall be established which will preserve good film quality.
d. After a full cleansing of the processor a film shall be exposed to a density of approximately one, with one-half of the film protected exposure. It will be developed and then kept near the unit and daily at least one test film (exposed under techniques identical with those used for the original test film) shall be compared with the original test film to evaluate the adequacy of the unit's developing capability and base fog level.
3. Processing deviations from the requirements of appendix D shall be documented by the registrant in such manner that the requirements are shown to be met or exceeded (e.g., extended processing, and special rapid chemistry).
4. Other requirements:
a. Pass boxes, if provided, shall be so constructed as to exclude light from the darkroom when cassettes are placed in or removed from the boxes, and shall incorporate adequate shielding from stray radiation to prevent exposure of undeveloped film.
b. The darkroom shall be light tight and use proper safelighting such that any film type in use exposed in a cassette to x-radiation sufficient to produce an optical density from one to two when processed shall not suffer an increase in density greater than 0.1 (0.05 for mammography) when exposed in the darkroom for two minutes with all safelights on. If used, daylight film handling boxes shall preclude fogging of the film.
c. Darkrooms typically used by more than one individual shall be provided a method to prevent accidental entry while undeveloped films are being handled or processed.
d. Film shall be stored in a cool, dry place and shall be protected from exposure to stray radiation. Film in open packages shall be stored in a light tight container.
e. Film cassettes and intensifying screens shall be inspected periodically and shall be cleaned and replaced as necessary to best assure radiographs of good diagnostic quality.
f. Outdated x-ray film shall not be used for diagnostic radiographs, unless the film has been stored in accordance with the manufacturer's recommendations and a sample of the film passes a sensitometric test for normal ranges of base plus fog and speed.
g. Film developing solutions shall be prepared in accordance with the directions given by the manufacturer, and shall be maintained in strength by replenishment or renewal so that full development is accomplished within the time specified by the manufacturer.
N.D. Admin Code tit. 33.1, art. 33.1-10, ch. 33.1-10-06, app D