4 Structure of the temperature calibrator
SIKA Dr.Siebert & Kühn GmbH & Co.KG
4.3 The metal calibration block
Both the dry well calibrators are fitted with an electronic temperature-controlled metal block. This metal block
is fitted with a 28 mm x 150 mm bore for holding the adapter insert. It contains one or several bores with
different diameters for thermically coupling thermometers of various thicknesses to the metal block. Good
thermal coupling between the block, the adapter insert and the thermometer is very important for keeping
measuring inaccuracies during calibration to a minimum. The metal block is thermically insulated against the
housing wall.
4.4 Integrated measuring instrument
Resistance thermometers, thermo elements and temperature transmitters must be operated with a measuring
instrument during calibration that measures the output signals such as thermo-voltages, resistance values and
standard 0(4)-20 mA signals and displays them in the form of temperature values. This temperature can then
be compared to the set calibrator temperature.
It is far more convenient to use our temperature calibrators with integrated measuring instrument. It performs
the tasks of an external measuring instrument and displays the temperature directly on the calibrator display.
Our precision temperature calibrators are available in two different configurations:
without integrated measuring instrument (TP 38… E)
with integrated measuring instrument (TP 38…)
Any TP 38… E can be upgraded with an integrated measuring instrument at our company at any time.
The integrated measuring instrument also permits parallel connection of a probe and an external reference
resistance thermometer. If the probe is too short for the block bore, for example, it is not in the homogenous
temperature range and cannot be calibrated. For this reason, an external reference is connected to the
integrated measuring instrument and parallely inserted into the block bore in the same depth. The temperature
of the reference, of the probe and the difference of the two are displayed.
The following probes can be connected to the integrated measuring instrument:
Resistance thermometers (RTD): Pt100, Pt 500 und Pt 1000 in 2, 3 or 4 conductor circuits
Thermocouples (TC) of the K, J, N, E, R, T, B, S, L and U types
0(4)-20 mA power signals from temperature transmitters (mA), with and without supply voltage
Temperature switches (switches) with "normally open" and "normally closed" contacts.
In addition to a thermocouple connector (refer to the circuit diagram), 4 mm sockets for plugs, cable lugs and
blank wires are available for connecting the probe.
The external resistance thermometer is connected using a 7-pole connector.
