1
GB
Temperature Dry Well Calibrators/Micro Calibration Baths
CTD9100/CTB9100
11263911 04/2007 GB/D
WIKA Operating Instructions Temperature Dry Well Calibrators/Micro Calibration Baths
5.4 Testing temperature sensors
A separate temperature measuring instrument
connected to the test specimen is required to
test the temperature sensors. By comparing the
temperature displayed at the external measur-
ing instrument with the reference temperature it is
possible to assess the status of the test specimen.
Remember that the test specimen requires a short
period of time until it absorbs the temperature of the
metal block or liquid bath.
It is not possible to calibrate
earthed thermal elements, because
the heating block is earthed and
any measurement would produce
incorrect results.
5.5 Start-up procedure
If the calibrator is not used for a longer period, it is
possible for moisture to enter the heating elements
due to the material used (magnesium oxide).
After calibrator transport or storage in a damp
environment, the heating elements have to be gently
brought up to operating temperature. During the
drying out procedure it has to be assumed that
the calibrator has not yet achieved the required
insulation voltage for protection class I.
The start-up set value is T
start
=120°C for a stop
period of T
n
=15 min.
5.6 Switching on the calibrator/micro
calibration bath
Connect the supplied mains plug to a mains
outlet.
Actuate the mains switch.
The controller is initialized
tESt appears on the upper
PV
display.
The version number, e.g. rL 2.2, appears on the
lower
SV
display.
Initialization is completed after approx. 5 sec., the
calibration mode
is then automatically displayed.
The instalLED heating and cooling elements
automatically adjust the metal block from the
room temperature to the set temperature set at the
controller.
5.7 Reference and set temperature display
Upper PV display:
The red, 4-digit, 7-segment display shows the
current temperature of the metal block/liquid bath.
Lower SV display:
The green, 4-digit, 7-segment display shows the
current set temperature of the metal block/liquid
bath.
Once the set temperature has been achieved, the
radiated heat energy from the metal block/liquid
bath is supplied by short firing pulses, thus ensuring
that the temperature inside is kept constant.
5.8 Stabilizing the reference temperature
The switch on time of the heater is displayed by the
red LED OUT 1.
During the heating up phase a constantly lit LED
displays the supply of heat energy, a flashing LED
indicates that the reference temperature has almost
reached the set temperature and the heat energy is
now being supplied at short intervals.
In order to guarantee excellent temperature stability,
the cycle time of the controller is set to low and the
control output is addressed on a regular basis.
Fig. 1: Reference and set temperature display
Fig. 1: LED OUT 1 displays
Fig. 14: Control occurs via PID algorithm