HD2108/HD2128
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V2.3
THE
PROBES
The instrument works with thermocouple probes of type K, J, T, N, R, S, B or E. The selection is
done using the TC SEL key.
The contacts of the thermocouple probe connector are polarized. They must be inserted on the
standard mignon socket located on the instrument in the correct direction. These probes are usually
marked with a + and – sign: These symbols must coincide with the corresponding symbols located
on the instrument's rubber protection.
The user can choose the unit of measurement for display, printing and logging among the allowed
ones: °C, °F or °K. Moreover, the voltage in mV generated by the probe (hot junction) or the
voltage in mV equivalent to the read temperature, and indicated at 0°C, can be displayed.
The
HD2128.1
and
HD2128.2
models have two inputs: the upper one is input "A", and the
corresponding temperature is displayed in the main line. The lower one is input "B", and the
corresponding temperature is displayed in the secondary line.
If two probes are used, they must be the same type of thermocouple.
T
EMPERATURE MEASUREMENT
In all versions the thermocouple hot junction is housed in the end part of the probe.
The response time for the measurement of the temperature in
air
is greatly reduced if the air is
moving. If the air is still, stir the probe. The response times are longer than those for liquid
measurements.
The temperature measurement by
immersion
is carried out by inserting the probe in the liquid in
which the measurement has to be performed; the hot junction is housed in the end part of the probe.
In the temperature measurement by
penetration
the probe tip must be inserted in the material, the
hot junction is housed in the end part of the probe. When measuring the temperature on frozen
blocks it is convenient to use a mechanical tool to bore a cavity in which to insert the tip probe.
In order to perform a correct
contact
measurement, the measurement surface must be even and
smooth, and the probe must be perpendicular to the measurement plane. A contact measurement is
hard to perform due to various factors: the operator must be experienced in handling the probe and
consider all the factors influencing it.
So as to obtain the correct measurement, the insertion of a drop of oil or heat-conductive
paste is useful (do not use water or solvents). This method also improves the response time.
Calibration of the temperature probe on line with the instrument
To calibrate the probes correctly, a knowledge of and abiding by the physical phenomena on which
the measurement is based is fundamental: this is the reason why it is recommended to abide by what
is reported below carefully, and only to perform new calibrations if technically proficient and using
the suitable equipment.
The instrument is provided with the FACT (factory) calibration only. The user is also able to
perform a USER calibration of insprobe. The calibration information is saved in the
instrument memory and not in the probe. The same correction is applied to any probe connected to
