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Figure A Temperature too low
Figure B Temperature just right
Figure C Temperature too high
Sample holder
silver wire
Firing plate (6)
7.3 Furnace calibration with
'Silver Test'
The sheathed thermocouple may be
subject to changes which affect the
furnace temperature, depending on
the mode and period of operation.
Check furnace temperature with the
'Silver Test' at least twice a year and
adjust if necessary.
For that purpose, the furnace
features P199, a special calibration
program.
Material required
(in the Temperature Checking Set 2)
(Article No. 544 903)
– Ivoclar Vivadent sample holder
– Silver wire, purity 99.99%
Procedure:
a) The furnace must be at operating
temperature (switched on for at least
60 minutes) and have a stand-by
temperature of 403 °C (757 °F) (e.g.
in P199).
b) Insert silver wire into the Ivoclar Vivadent
sample holder (see also notice enclosed in
the Temperature Checking Set 2).
c) Select P199 (Silver Test program)
d) Press this key and place the firing
tray with the silver strip in the
centre of the firing plate (6).
e) Press START (if error message Err 14 appears,
the furnace temperature is still too high for
the 'Silver Test' (>410 °C/770 °F).
The furnace closes automatically at the
correct temperature and the program starts).
If the silver wire has started to melt
(and has a ‘pitted’ appearance) at the end
of the program, the furnace temperature is
correctly calibrated (Figure B). If not,
recalibration is necessary.
Recalibration
A change in temperature of *50 °C
(*90 °F) is possible in the Programat
P200. Select program P199 to activate
the calibration keys ‘+’ and ‘–‘. The
program must not be started for this
purpose.
The latest calibration value is indicated in the
input field (70) if the cursor (80) is moved to
the parameter field L (79) by means of the
arrow keys.
– If the silver wire has not started to melt
after the 'Silver Test', recalibrate using
the ‘+’ key (A)
– If the silver wire has melted down to a ball
after the 'Silver Test', recalibrate using the
‘–‘ key (C)
Every time a calibration key is pressed,
the set temperature changes by 1 °C
(1.8 °F). Experience has shown that a
recalibration of 5 °C (9 °F) is appropriate,
which means pressing the relevant key
five times.
While the calibration keys are in use, the
calibration value in °C (°F) is shown in the
input field (70). Entering the calibration
value does not have to be confirmed with
ENTER. Repeat the ‘Silver Test’ until the silver
wire starts to melt correctly (B).
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