Techkon SpectroDens Manual page 18

Menu: Calibration
Prior to every series of measurements a calibration should be carried out. After a
calibration the device is long term stable, however it is recommended to perform
a calibration before starting a new measurement task just to be sure the device is
working properly.
For density measurements the calibration is carried out on paper white. This will
ensure that the density values are in direct ratio to the ink thickness which is applied
on the paper. When there is a change in the paper type, a new calibration has to be
done. Only in a few cases density measurements are referenced to an absolute white
standard.
A calibration is as easy to carry out as a measurement: Select the "soft key" Calibra-
tion and place the device with the measurement head on top of an unprinted area
of the paper sheet. The calibration can be started now by pressing either the Enter
button or the green Measurement button. After one second there will appear a win-
dow with the message that the calibration has been done. The device is now ready for
measurements. The message window will disappear with the next measurement.
During the calibration process always take care that the instrument is on a flat, stable
surface and that the material backing the paper is the same as for the following mea-
surements (white, gray or black). When the paper sample is printed on both sides, it
is recommended to use a black backing material in order to avoid misreadings due to
color shining through the back of the opaque paper.
Page 18 Manual TECHKON SpectroDens Chapter 1 – How to use SpectroDens