DeltaOHM HD31, Руководство по эксплуатации

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HD31
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V1.6
4 THE PROBES
The probes of the instrument are equipped with an “intelligent” module acting as interface be-
tween the probe and the instrument. Inside the module there is a microprocessor circuit with
permanent memory performing different functions:
• allows the instrument to recognize the type of connected probe: Pt100, thermocouple, hu-
midity probe, pressure probe, anemometric probe, photo/radiometric probe, ...;
• stores into memory the probe calibration data: in this way the probe can be indifferently
connected to the three inputs of the instrument or to another instrument with no need to
be recalibrated;
• recognizes the instrument with which it was calibrated (user-calibration);
• maintains the factory-calibration data and those concerning the last calibration made by
the user, with the possibility of choosing one of the two calibrations for each of the probes
connected to the instrument;
• stores into memory a serial number allowing the unique identification of the probe, a useful
feature in case several probes of the same type are simultaneously used.
The recognition of SICRAM probes takes place when the instrument is started or after a reset.
SICRAM probes are supplied factory-calibrated and don’t normally require further interventions
from the user. Nevertheless, a new calibration can be carried out if needed. See chapter 13 for
user-calibration of the probes.
4.1 PRT T
EMPERATURE
P
ROBES
Pt100 probes with SICRAM module can be connected. The probes have a 4 wire connection and
the excitation current is chosen in such a way as to minimize the sensor’s self-heating effect.
If your instrument needs to be connected to sensors that are not equipped with SICRAM mod-
ule, one of the following two accessories will have to be placed between sensor and instru-
ment:
• TP471 : “intelligent” module with microprocessor and permanent memory, designed for
4-wire Pt100 Platinum sensors ( PRT ).
• TP47 : connector without microprocessor and memory, designed for 4-wire Pt100 and 2-
wire Pt1000 Platinum sensors ( PRT ).
TP471 and TP47 are provided with fairlead and cable grommet for 5 mm max diameter cables.
Proceed as follows:
1.
Unscrew the fairlead and pull the cable grommet out, remove the identification label, un-
screw the ring nut on the opposite side of the module/connector.
Fig. 4.1.1: opening the module/connector
2. Pass the sensor cable through the fairlead and cable grommet.
3. Open the two module/connector shells and connect the PRT sensor to the printed circuit as
shown in the figures below. Take care that the welding is clean and skillfully made.