Technical data

Densitometric functions

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4.9

4.9 Printing plate

The function ‘printing plate’ is used for measuring the dot area on printing plates for offset printing.

The operating procedure is similar to the procedure of the function ‘dot area’, but instead of the

paper white you have to measure the plate ground of the printing plate. The measurements of the

solid tone and halftone have to be performed on the corresponding fields on the printing plate.

The calculations of the dot area is done using the are the Yule-Nielsen. For the printing plate you can

define a special Yule-Nielsen-coefficient which can be different to the coefficients of the dot area

function. On most printing plates you will achieve good results with coefficient values from 1.08 to

1.24 (typically 1.15).

For excellent results you have to determine the Y-N-coefficient for your printing plate using a

microscope for measuring the dot area.

You can also switch off the Yule-Nielsen-correction by setting the Y-N-coefficient to 1.0.

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Select automatic or manual filter selection under Settings k Color or in the selected

densitometric function under the menu line Color.

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Enter the Yule-Nielsen-coefficient in the function ‘Printing plate’ under the menu line Yule-

Nielsen.

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Procedure:

• Select the menu line Printing plate by turning the <Control ball>.

• Activate the selected function by pressing the <Measurement key>.

• Select the menu line Measure plate ground by turning the <Control ball>.

• Position the measuring aperture on the plate ground and initiate a measurement by pressing the

<Measurement key>.

• The display Plate ground measured is shown for about 1 second.

• Position the measuring aperture on the solid tone patch and initiate a measurement by pressing the

<Measurement key>.

• The density value of the solid tone patch is shown on the display.

• Position the measuring aperture on the halftone patch and initiate a measurement by pressing the

<Measurement key>.

• The dot area of the halftone patch is shown on the display.