Resistance Standards
Design and Construction Notes
Design and Construction Notes
The 742A Series are constructed of arrays of Fluke wirewound precision
hermetically-sealed resistors. No adjustable resistors of any kind are used.
Each 742A is built with a temperature coefficient near zero at 23
°
C. To further
reduce errors caused by temperature changes, the binding posts are constructed
of low-thermal emf material.
Features
Figure 1 shows a front panel view. Figure 2 shows a rear panel view. Table 2
describes binding post functions. Table 3 describes the rear panel labels.
Figure 1. Typical Front Panel View
Table 2. Functions of the Binding Posts
742A Binding Post
Function
CURRENT HI
CURRENT LO
SENSE HI
SENSE LO
CHASSIS GROUND
Input for the current source from an ohmmeter
Input for the current source from an ohmmeter
Measurement point for a four-wire ohmmeter
Measurement point for a four-wire ohmmeter
Connected to the case for shielding
3
