Operating Manual

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10.6 Checking the development process
and film archiving properties
Besides exposure technique, many aspects influence the quality of the final radiograph.
An important factor is the development system. Monitoring and quantifying the proper
functioning of a development system is an essential part of quality control, as a properly
exposed radiograph can be spoilt if the processes that follow are performed incorrectly.
For the monitoring of the development process and archival properties of X-ray-films,
Agfa has produced two methods: the so-called PMC-strips, and the Thio-Test.
Both methods are based on the international standard ISO 11699 part 2, and the
European standard EN 584 part 2, which describe a standard development process and
the means to control its execution.
PMC-strips to check the developing process
To facilitate ongoing quality control, and ensure compliance with existing standards on
systems classification, certified PMC-strips are used to monitor the development process.
PMC is short for Processing Monitoring Control.
The purpose is to:
• demonstrate conformance with the standard film system as described in the
standards ISO 11699 or EN 584
• demonstrate the consistency of the development system
• monitor and promote uniformity of the various development systems in
different locations
• initiate timely corrective action if deviations occur
PMC-strips are film strips that have been “ pre-exposed” in a regular step-pattern by the
supplier, under special conditions and within narrow tolerances, but have not as yet been
developed. They are supplied with a certificate of compliance with EN 584-2 and
ISO 11699-2.
In the development system to be checked, a PMC-strip is processed routinely in a way
identical to a normal radiograph. Finally, the various densities are measured with
a densitometer.
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NDT-E (economy) film processor
In order to limit any detrimental effects on the environment, Agfa has developed the “Eco”
(Ecology and economy) designated processors. Here, too, equipment and chemicals are
carefully matched, thus complying with strict ecological requirements such as a maximum
of 50 mg silver per square metre of processed film, for the disposal of rinse water.
This figure for silver content is at least fifteen times lower than for conventional developing
systems. This is achieved through the considerably improved (cascade) fixing process,
which additionally results in a bigger quantity of recovered silver.
Furthermore, measures have been taken to save on energy, chemical and water usage, the-
reby making the “eco” range of film processors as environmentally friendly as possible.
Figure1-10 shows the schematic lay-out of this high-tech processor.
The “S eco”-version has a 50 % higher production capacity than the U-version.
A very useful option is its suitability for use in daylight, in combination with a matching
film feeding system.
1 Film feeder
2 Film surface scanner
3 Developer tank
4 Rinse tank
5a/b Fixer tanks
6 Final wash tank
7 Infrared dryer
8 Film exit
9 Film receiving tray
10 Fixer pump
11 Developer pump
12 Overheating protection
Fig. 1-10. Schematic layout of the Agfa NDT S eco processor