Standard thermometer
Models CTP2000 and CTP9000
Applications
■
Comparative calibration in dry well calibrators, tube
furnaces and liquid baths
Special features
■
High stability
■
Low drift, long service life
■
Wide temperature range
Calibration technology
WIKA data sheet CT 61.10
Description
Calibration by means of an external standard
thermometer
The WIKA standard thermometers are particularly suited
for applications in industrial laboratories. They enable easy
comparative calibration in our baths, in tube furnace and in
dry well calibrators.
The use of an external reference thermometer is
recommended, particularly for the calibration of short
temperature sensors. Thus the errors due to the radial and
axial temperature distribution in the temperature conditioning
unit are considerably reduced.
Platinum resistance thermometer model CTP2000
For calibration, the test items and the standard thermometer
are brought to the same temperature in a temperature
conditioning unit.
As soon as a stable temperature is reached, the test items
are read or their output signals are measured (resistance,
thermoelectric voltage, standard signal) and compared with
the standard thermometer.
Using this comparison method, the measuring uncertainty
can be considerably reduced because not only the display of
the temperature conditioning unit is taken into consideration.
Data sheets showing similar products:
Reference thermometer; model CTP5000; see data sheet CT 61.20
Page 1 of 4WIKA data sheet CT 61.10 ∙ 01/2015
Models
Platinum resistance thermometers model CTP2000
Features
The measuring resistor consists of a platinum winding of
highest purity.
All parts are pre-aged in order to remove contamination
and distortions.
Measuring technology
The 4-wire design oers an optimum connection solution for
resistance thermometers. The measuring result is aected
neither by the lead resistances nor the temperature-
dependant uctuations.
The electrical connections are welded in order to minimise
the transition resistance. The connecting wires are bound in
a 2 m long, shielded connection cable.
Principle of a platinum winding
Thermocouple model CTP9000
Features
The standard thermometer is a type S element whose
nominal composition consists of Platinum-10 % Rhodium
(positive leg) against Platinum (negative leg) and belongs
to the group of noble thermocouples.
It is characterised by its high stability.
The quality of the thermowell used is essential for stabil
ity at high temperatures. For this reason, the high-purity
aluminium oxide ceramic C 799 is used.
The type S thermocouple, besides the low ageing drift, also
oers the advantage of a low basic tolerance.
Measuring technology
During measurement it must be ensured that the
compensating leads from the measuring point to the
cold junction consist of substitute materials which have,
in a limited temperature range, the same thermoelectric
properties as the materials of the thermocouple. Therefore,
at this transition, there is no thermoelectric voltage.
This voltage is only generated at the point where the
compensating leads are connected to normal copper leads.
-
Thermocouple model CTP9000
Calibration
Your standard thermometer should be calibrated once a
year.
If it is subject to high mechanical stresses, it should
be calibrated immediately to guarantee the measuring
uncertainty.
Page 2 of 4 WIKA data sheet CT 61.10 ∙ 01/2015