DayTronic 3000 series, Instruction Manual

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Daytronic Corporation
Calibration Resistor.
If a fixed resistor is shunted across one arm of a strain
gage bridge, it produces an unbalance equivalent to that of a particular value of
mechanical input. If this
Equivalent Input
value is accurately known, it can be used
as a reference point for shunt calibration of the system. Upon completion of
installation of the transducer and its associated cabling, the user can:
Perform an overall
dead weight
calibration using a precisely known
value of mechanical input. The calibration can then be transferred to the
installed calibration resistor for convenience in subsequent checking.
Replace the installed calibration resistor with one (or an equivalent
resistance value) supplied by the transducer manufacturer to achieve a
precisely known
Equivalent Input
allowing the instrument sensitivity to
be adjusted correctly.
Determine the
Equivalent Input
value for the installed calibration resis-
tor, knowing the transducer sensitivity, and adjust the instrument sen-
sitivity accordingly.
A precision 59-kilohm calibration resistor is installed in the 3178 at the factory.
The installed resistor can usually be used even though the transducer calibration
data mentions some other resistance value. In Section 3 of this manual, the tech-
niques described above are demonstrated. If, however, the installed value of
calibration resistor is not appropriate for the transducer and measurement range to
be used, the 59-kilohm resistor should be replaced at this time. The calibration
resistor is mounted on terminals located at the front edge of the conditioner
printed-circuit board. It can be accessed by removing the instrument front panel.
Note:
Lebow
1600 Series
Rotary Transformer Torque Transducers are supplied
with the appropriate calibration resistor integral to the transducer. When this type
of transducer is used with the 3178, it is not necessary to remove the 59-kilohm
resistor internal to the instrument. The Lebow calibration resistor can be appropri-
ately connected to the 3178 calibration circuit via the transducer cabling. Refer to
Figure 4 and the following section.
Transducer Cabling.
Cabling to the transducer is accomplished via the
supplied instrument I/O connector. The I/O connector pin numbers and functions
are given in Figure 4. When Daytronic 400 or 500 Series Transducers are used,
factory-wired cables are available as shown in Figure 4. The Daytronic 82S Cable is
for use with Lebow
1600 Series
Rotary Transformer Torque Transducers. This
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