Fluke Hart Scientific 1523, Technical Manual

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Digital Communication Interface
Wiring
6 Digital Communication Interface
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Special Note on Using grounded and bare junction thermocouples with
RS-232:
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1. Use the 1523/24 demand log and auto log functions to avoid connecting to a
computer when using grounded junction or bare junction thermocouples. Once
the readings are complete, connect the RS-232 cable and upload the data to the
personal computer.
2. Use an optically coupled isolator that is connected between the personal
computer and the RS-232 cable to the 1523/24. The Isolator breaks the
electrical ground loop by only communicating data, using light. Refer Section
1.8 for contact information to purchase the Isolator or if you have any further
questions.
3. Use a laptop computer running on its battery without an AC adapter. This may
provide enough isolation to minimize the grounded thermocouple measurement
errors. The user should test this scenario by taking measurements with and
without the RS-232 cable connected to the 1523/24.
6.1 Wiring
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