Operating manual DigiDens T6CR
Colour reflection mode:
In colour reflection mode you can measure densi-
ties and percentages of colour control fields on
reflective media.
If the display shows ‘DigiDens Cal CR’ after
switching on, the colour reflection mode is alrea-
dy active. If the device is in transmission mode
after switching on (this depends on the mode,
which has been active when switching off the
device the last time), press button P to enter the
colour reflection mode (‘Cal CR’ on the display).
In this mode 3 specific colour light sources (filter
behaviour like Kodak Wratten Tricolor Filters) are
switched on separately and the light sensor
examines the remission.
The DigiDens T6CR possesses the following
important elements:
- 3 Pushbuttons M, C, P,
- 16-digit LCD-display,
- sensor head with 3 colour light
sources and lightsensor,
- Battery case for 3 mignon cells
The three pushbuttons M, C and P are used for 2
functions each. The second function is initiated
by pressing the button for a longer period of
time (>4 seconds).
Pressing the red pushbutton P(power) switches
between the 5 different display modes. Second
function is the switch to Transmission (‘T’).
Switching off the device needs to press butten ‘P’
even longer.
The center button C (calibrate) calibrates the
device. Second function is the menue mode to
modify some parameters.
Pressing button M(measure) initiates the measu-
reing process, the second function stores the
measured value as a reference. For display
mode 1, 2 and 4 only the dominant colour
separation component of the reference is sto-
red (So you can have 4 references for the
four separation colours). For display mode 3
and 5 the complete colour with its 4 separati-
on components is stored.
The measured value and the parameter modifi-
cation is displayed on the 16-digit LCD-display.
You find the four values for cyan, magenta, yel-
low and black next to each other on the display.
Densities are displayed with two fraction digits,
percentages are displayed without fraction part.
There are 5 display modes:
1. Maximum display densities:
after a measurement and always after calibra-
tion (zero adjustment) only the colour with the
maximum (dominant) value is changed in the
display. This value is indicated with a leading
arrow.
This mode is suitable for measuring colour
control fields of pure printing inks, because
values of other separations are left unchan-
ged in the display.
2. Maximum display percentage:
The percentage of the dominant separation
colour is displayed, the values of the other
separations are left unchanged. Percentages
only can be measured after solid colour cali-
bration of this separation and only on pure
separation colours (control wedges).
3. All separation Display:
In this display mode all separation compo-
nents of the measured colour are displayed.
Attention: Even pure separation inks do con-
tain components of other separation colours
(e.g. magenta ink also contains yellow and
cyan).
4. Differential display (to reference):
In this mode the difference of the dominant
separation to the reference colour component
is displayed. The display of the other separati-
ons is left unchanged. The differences are
always displayed with its sign. After each
white calibration, the absolute values of all
reference colour components are displayed.
5. Display of weighted distance in RGB-colour
space:
In a multi dimensional colour space every
colour has its unique position. Two colours
do have a distance value, which depends on
the similarity of this two colours. The more
similar this colours are, the smaller the
distance. This display mode calculates in CIE-
Lab and the distance is delta E.
Also a + or - is displayed behind the distance
value, which indicates, if the currently measu-
red colour is darker (+) or brighter (-) than the
reference (luminance indicator).
Pressing the button ‘P’ shortly, switches bet-
ween the 5 display modes.
The functions in details:
Button P:
The DigiDens T6R is switched on with this but-
ton. If you switch on the device, you first will see
the indication ‘Wait’ to hold the button. On the
right of ‘Wait’ you find the version number of the
software (e.g. V5.R). If you release the button
before the display switches to ‘DigiDens Cal’,
the device switches off (to prevent the device
from being switched on accidently). Now the
device is ready and it should be calibrated for
the mode you want to use it (here ‘CR’).
The switch between the 5 display modes also is
done with this button.
Holding the button for about 4 seconds leeds to
the transparent mode (‘T’), if currently in colour
reflection mode. To switch off the device, press
this button ‘P’ even longer, until you see ‘Down’.
Now you can release the button and the device is
switched off. There is no real need to switch off
the device manually (whenever no measurement
is done, the device runs in low energy stand by
and switches off automatically after about 8
minutes).
Button C:
With this center button Cthe white and solid
colour calibration is done. The white calibration
is valid for all 4 separation colours. The solid
colour calibration must be done separately for
every separation colour !
The second function is the menue function to
modify some parmeters...
Calibration for the reflection mode ‘CR’:
Make sure, your densitometer is in colour reflec-
tion mode ‘CR’. Position the measuring head
above your white, then press button ‘C’. The
white alignment is done, the display shows densi-
ty 0,00 for every separation and the arrow points
to black as a default. Now you calibrate the solid
separation colours: Place the measuring head on
a solid separation colour and press button ‘C’
again. Now the white calibration value is referen-
ced as 0%. The solid colour value is references
as 100%. Only for the separation colours
which have been ‘solid colour calibrated’, per-
centage measurements are possible. The other
separations permanently show 0%.
Now the calibration is finished. If white is inter-
preted as solid colour (wrong handling, very few
cases), switch to transparent mode with the but-
ton P and back to colour reflection mode to reset
the calibration. A new calibration of white invali-
dates the old solid colour calibration too.
Menue modes:
If you hold the button Cfor longer than 4
seconds, the menue mode is initiated. This mode
enables the user to modify some parameters.
The first step is
DotGain (Soft Dot):
You see ‘DotGain’ here followed by a ‘R’ and
the percentage of Dotgain for the middle tones
(around 50%) on the display. Factory setting is
0.0%. With button Myou can increase this value
in steps of 0.5%. With button Pyou can decrease
this value in steps of 0.5%. The DotGain value is
valid for all 4 separations.
Pressing button Cswitches to the next parameter
(step2)Select. The Select can be modified by
pressing the M (forward) or P (backward) button.
Select A=Autoselect (factory setting) or the indivi-
dual colors (C,M,Y,K) here.
For negative printing plate-measurements you
can use the next select Neg. THe select Abs
stand for absolute densities and can only be
used, if you also ordered a reference white cera-
mic tile (rarely used)
Pressing button C switches to the 4 colour-indivi-
dual Yule Nielsen Factors (an improved and
generalized variant of the Murray-Davies formula)
for percentage measurements. This formula allo-
ws the variation of paper and ink parameters The
parameter varies from 0.6 up to 3.0. Factory set-
ting is the medium value 1.2. Choosing the right
parameter needs some experiments in the begin-
ning (Smaller values increase the mid tone per-
centage values).
Pressing button Cagain leads to the next para-
meter (step3) Slope adjustment:
The slope adjustment is also separate for the four
colour separations. This feature enables the user
to adjust the density of ‘DigiDens’ to another
densitometer. Despite the precision of
‘DigiDens’, there might be a need to vary the
density values slightly for compatibility purposes.
The slope value can be varied between 1 and
200. The factory setting is 100, which means ori-
ginal slope.
With button Myou can increase the slope, each
step increases the density about 0.5% (e.g. den-
sity 2.00 is increased to 2.01 by one step). With
button Pyou can decrease the slope in the same
way.
Service parameters (factory settings):
some parameters only can be changed when the
unit is startet in the reset mode (pressing button
M with button P simultaniously, when switching
on). Then you have access to parameters you
better only change with factory guidance.
The 3 internal Slope1 parameters change the
responding curve. The next 3 internal Slope2
parameters do the same as the external slope.
The following 3 color parameter influence the fil-
ter behaviour of the instrument.
The next 3 WT (White Threshold) parameters
decide when to interpret white and when to inter-
prete solid colour while calibrating.
With these service parameters component variati-
ons of the densitometers are balanced.
Pressing the button Cfor a longer period of time
(>4 seconds) leaves the menue mode and saves
the current parameters (you see ‘Save’ on the
display). If you want to leave the menue mode
without saving the parameters, switch off the
device by pressing button Puntil you see ‘Down’.
Button M:
This button is the measuring button. In the mea-
suring mode (not menue mode, where button M
is the increment button) button Minitiates the
measuring process. During this time a ‘w’ for wait
is displayed on the display in the first digit to indi-
cate, that the measuring process is in progress.
After the measurement the first digit shows a ‘D’
in display mode 1 and 3, a % in display mode 2.
You can store a measured value as a referen-
ce by holding the button M for a longer period
of time (about 4 seconds) until the leading
digit shows a ‘R’.
For display mode 1, 2 and 4 only the dominant
separation of the reference is stored and for dis-
play mode 3 and 5 all color components of the
measured value are stored. Reference colours
are needed for the difference calculation in dis-
play mode 4 and delta E calculation in display
mode 5.
M C P
