ISO 11928-2 pdf download – Micrographics一Quality control of graphic COM recorders – Part 2: Quality criteria and control

ISO 11928-2 pdf download – Micrographics一Quality control of graphic COM recorders – Part 2: Quality criteria and control.
3 Terms and defInitions
For the purposes of this part of ISO 11928. the definitions given in ISO 6196 and the following apply.
3.1
test tram.
data file which generates test images on a CO’I recorder
4 Evaluation
4.1 General
The evaluation of the quality of a graphic COM image is a complex task. Various conditions can occur in a graphic COM recorder that are not found in alphanumeric COM recorders, which can be evaluated with the use of a form slide, Many graphic COM recorders have no provision for a form slide and if they are to be evaluated all measurements wil have to be taken from the microform image produced by the image generator.
NOTE Ills customary br raphlc CCM recorders to produce negative agpearlng fIlm Images. For clarity of presentation, the examples in figures 1-5 have been reproduced as poeiLrve-pearing Images.
4.2 Test runs
The tests described in 5 shall be used initially to evaluate the quality of a graphics COM recorder, and then subsequently to monitor its quality. They may be used as a routine procedure. or for determining the reason for unsatisfactory Output.
The results of the initial test runs shall be retained as a reference sample for comparison with subsequent runs. Where this test run gives results outside system tolerances (see 4.3). then the system shaM be adjusted and the initial tests repeated 1til results are within system tolerances.
Before tests are run, the operator shaM ensure that the film processor is in proper working order.
The test frames shall be plotted using the minimum me width recommended by the manufacturer for the te of test frame being plotted.
The images generated during testing shall be examined, and if any shows sr9nificant signs of deterioration in quality compared with the reference sample. the entire set of images shall be rerun and examined.
Results of test runs shall be retained for audit purposes.
4.3 System tolerances
System tolerances for tests specified io 5 shall be agreed with the equipment suppliers and documented along with the results of the initial test runs.
Values obtained from tests specified in 52.3 should be in accordance with Table I.
5.1.2.4 Linearity
Measure the horizontal and vertical distances of each grid line intersection from the lines AD and CD respectively. Compare these measurements with the computed deal distance for each and check that any errors are within system tolerances (see 4.3).
5.1.2.5 Line width
Traverse the line and measure its minirnisil and maximum thickness. Check that the measurements are within
system tolerances (see 4.3).
5.1.2.6 Alignment of Image centre line to film edge
Align the X axis of the microscope with the reference edge of me him. Measure the distance from the reference edge to the horizontal centre line at the centre of the line and at the endpoints. Check that the measurements are thin system tolerances I see 4.3).
5.1.2.7 Image centering
Check thai the measurements in 5.1.2.6 correspond with the centre line of the film, to within system tolerances (see
4.3).
For aperture cards, similar measurements should be made also for the vertical centre line both being referred to the card edges.
5.2 Test for resolution, Iegib4liIy and density
5.2.1 ResolutIon
Using a microscope th a magnification of 1 to 3 times the ettective reduction ratio, examine the targets at the centre and in each corner of the frame (see figure 2). Note the letter of the smallest resolvable group of lines in each tar get, following the method described In ISO 3334.
NOTE Groups are designated by letter rather than numerical value because the resolution recorded Is a function of image size. The actual resoêjlion in line pairs per milbnetre can be determined by comparing the results obtained with a table sopplied by the manufacturer 01 the COM recorder.
5.2.2 Legibility
Examine the groups of letters e and note the group number of the smallest letter that is fuly legible.
5.13 Density
Using a densitometer, measure the minimum and maximts’n diffuse density in accordance with ISO 5-2 and ISO 5.3.