Calibration
SpectroPlate is factory-side calibrated. A
white calibration
adjusts the digital came-
ra module. The
screen calibration
is for exact adjustment of dot percentage measu-
rements towards the reference plate
Fogra Measuring Bar FMB
. The calibration
remains permanently and the devices are long-term stable. This means that there are
no time intervals for re-calibration necessary.
To ensure the correct operation of the device, we recommend to perform check-up
measurements once a month. Before measuring make sure that the measurement
aperture is free of dust. In case it has to be cleaned use oil-free, clean compressed air
or an optics brush.
The suitable reference for check-up measurements is the offset
sample plate
Fogra Measuring Bar FMB
from the research
institute Forschungsgesellschaft Druck, fogra e.V., München.
It includes two percentage wedges, one periodic AM screen and
one non periodic FM screen.
It includes a documentation with a protocol listing reference
values taken with a laboratory instrument by the institute.
Fogra Measuring Bar can be ordered over the internet at
www.fogra.org.
fogra Forschungsgesellschaft Druck e.V.
Streitfeldstr. 19 • D-81673 München/Germany
Telephone: +49 (0)89 43182-160 • Telefax: +49 (0)89 43182-100
http://www.fogra.org
We recommend to make five measurements per measurement patch and take the
average value in order to level out measurement deviations caused by inhomoge-
neous percentage patches due to the production process of the FMB. The averaged
measurement results of SpectroPlate have to be within the following tolerances:
AM screen (periodic): +- 0,5 %
FM screen (non periodic): +- 1 %
Manual TECHKON SpectroPlate Chapter 1 - How to use SpectroPlate
Page 13
