ISO 11928-2:2000 pdf download
ISO 11928-2:2000 pdf download.Micrographics – Quality control of graphic COM recorders — Part 2: Quality criteria and control.
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 ideal 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 minimum 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 the film. 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 within system tolerances (see 4.3).
5.1.2.7 Image centering
Check that 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, legibility and density
5.2.1 Resolution
Using a microscope with a magnification of 1 to 3 times the effective 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 target, 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 resolution in line pairs per millimetre can be determined by comparing the results obtained with a table supplied by the manufacturer of the COM recorder.
5.2.2 Legibility
Examine the groups of letters “e” and note the group number of the smallest letter that is fully legible.
5.2.3 Density
Using a densitometer, measure the minimum and maximum diffuse density in accordance with ISO 5-2 and ISO 5-3.
NOTE For thermally processed film measure visual projection density.
Table 1 gives acceptable values.
5.3 Test for radial recording
Take measurements to check that all lines are of equal density and are continuous and straight, without signs of misaligned butting, and whether the lines meet in the centre and are parallel in each line pair.
5.4 Test for curved lines5.4.1 Introduction
The test frame (see figure 4) is designed to check the system’s accuracy in producing curved lines.
5.4.2Method
Measure the eight radial lines of each circle to check that the distance from circumference of a circle to theis the same along any radius.
Take measurements to check whether in the circles drawn with double lines the distance between the two lines isconstant.
5.5 Test frame for measuring character display and rotation
Examine the lines of characters. Check for distortion and poorly formed characters, in the character size grid and inthe corner patterns.
It is important to ensure that raster COM-generated images will duplicate satisfactorily when exposed on a duplicating machine at intensity settings compatible with those for source-document microforms.
The requirements for the density of source-document microforms specified in ISO 3272-2 are not necessarily applicable to COM-generated images. The line density of a COM-generated image cannot be measured with instruments normally available to 0CM users. The correlation of line characteristics and duplicating exposure is complex, and can vary with the type of equipment and its optical characteristics.
The best method for a user and supplier to adopt in agreeing density values for COM-generated images is first to assess master and duplicate or print source-document microforms that comply with ISO 3272-2 and then to compare the characteristics of the COM-generated image so produced with the source-document image. Production of the COM-generated master image may then be adjusted to produce images of agreed quality.
