12
WIKA operating instructions, model CTD9100-1100
14030725.02 08/2019 EN/DE
EN
After approx. 5 secs, the initialisation will be complete and
the
calibration mode
will automatically be displayed.
The built-in heating or cooling elements will temper the metal
block automatically from room temperature to the controller’s
set temperature.
6.3 Start-up procedure
If the calibrator is not used for a long time, because of the
materials used (magnesium oxide), moisture can penetrate
the heating elements.
Following transport or storage of the calibrator in moist
environments, the heating elements must be taken to higher
temperatures slowly.
During the drying process,it should be assumed that the
calibrator has not yet reached the required insulation voltage
for protection class I. The start-up set point is T
anf
= 400 °C
[752 °F] with a holding time of T
n
= 15 min.
6.4 Temperature switch test
It is possible to control the intervention temperature of a
temperature switch by the
“Switch-Test”
function.
1. Insert the temperature switch in the most suitable hole of
the insert.
2. Connect the temperature switch electrical output cables to
the terminals.
3. Turn the calibrator on.
4. Set the intervention temperature and check the release by
the lighting of the indication light.
5. The temperature switch release values are recorded. In
order to display the recorded value, refer to the procedure
explained in chapter 7.2.2 “First level - General settings”
till
“SW ON - SW OFF”
.
⇒
Press the button
[▲]
and
[▼]
at the same time in order
to reset the
“SW ON - SW OFF”
values.
6. Refer to item 7.2 “Programming (Main menu)” or
7.2.2 “First level - General settings” to set ramps in order
to reduce the ascent rate and descent rate of temperature
to test the temperature switch
6.5 Testing of temperature sensors
To test temperature sensors, connect a separate
temperature-measuring instrument to the test item. By
comparing the temperature displayed on the external
measuring instrument with the reference temperature,
there is evidence of the status of the test item. This ensured
that the test item requires a short time until it reaches the
temperature of the metal block.
6.6 Positioning of the probe
The sleeve is made in CERAMIC and it has different holes
on the inside to make it possible to calibrate various types of
probes. The function of this block is to make the temperature
uniform. It is also possible to calibrate probes of different
length by adapting the depth of the holes. A customized
sleeve can be ordered at the manufacturer.
A customised sleeve can be ordered at the
manufacturer.
After the furnace generally been installed, the insert and
the ceramic tube insulation may be inserted. Carefully insert
the sleeve and the upper insulation into the Ceramic tube.
Prevent dirt or other foreign materials between the block and
the ceramic tube.
The insert replacement tool consists of a stainless steel
rod with a threaded end, which is screwed into the top of
the insert. The sleeve has to be inserted in this way that
the grooves are directly adapted to the control and cutout
thermometer. Insert the ceramic tube insulation on the top of
the sleeve. Centre the holes of the upper insulation with the
holes of the insert.
Whenever the calibrator has to be moved,
remove the sleeve and the ceramic tube in order
to prevent breakage.
To obtain the best results for the calibration, following advises
are important:
■
The diameter of the hole in the calibration block is at least
1 mm bigger than the diameter of the probe (see Fig.1).
■
The sensitive element of the thermometer is in the best
position, if the probe is inserted down to the bottom (see
Fig. 2).
When the probes length is shorter than the length of the hole
in the sleeve, the reference sensor should be on the same
height as the test item. Moreover the thermometers have to
be as close together as possible (see Fig. 3).
■
The temperature difference is proportional to
the difference between the diameter of the
probe and the diameter of the hole
■
The test item has to be inserted before the
set temperature is reached, otherwise this
can cause instabilities or a breakage of the
sensitive element.
6. Commissioning, operation