Ohms Functional Description - Fluke 5700A Series II Service Manual

5700A/5720A Series II Calibrator
Service Manual

2-15. Ohms Functional Description

Two assemblies function as one to supply the fixed values of resistance:
All of the resistance values except the 1 , 1.9 , and short are physically located on the
Ohms Main assembly. The 1 , 1.9 , and short are physically located on the Ohms Cal
assembly. The desired resistance is selected by relays on these Ohms assemblies and is
connected to the Calibrator binding posts by relays on the Analog Motherboard. The
Ohms Cal assembly also contains the appropriate circuitry to enable the Calibrator to
perform resistance calibration. Once calibrated, the Calibrator output display shows the
true value of the resistance selected, not the nominal (e.g., 10.00031 k , not 10 k ).
Four ohms measurement modes are available. For the two-wire configuration,
measurement with or without lead-drop compensation sensed at the binding posts of the
UUT (using the SENSE binding posts and another set of leads), or at the ends of its test
leads is available for 19 k and below. Four-wire configuration is available for all but the
100 M value.
2-12
Ohms Main assembly (A10)
Ohms Cal assembly (A9)