Section 1-Introduction and General Description
General Description
The 4910 and 4911 DC Voltage Standards are
based on the latest zener-diode technology. Their
four separate 10V outputs are fully independent,
but can if required be averaged to provide avery
low noise 10V output on separate front-panel
terminals. The provision of both individual and
average outputs enables direct inter-comparison
between the cells at the output terminals, allowing
excessive drift in any cell to be detected without
the use of higher accuracy standards. The
individual outputs -are adjustable to within
microvolts of one another, so that inter-
comparison is possible to avery high level of
accuracy.
In addition to its four individual cell outputs and its
average 10V output, the49 10 also features IV and
1.018V outputs, and alow-impedance 10V output
with 4-wire sensing.
In their normal operating mode, the units can be
powered from an ac line supply or from their
internal batteries. Both models also feature a
special low-powertransit mode,which can be used
during transportation or shipment of aunit to
maintain its calibration. In transit mode, power
can be derived from the unit’s internal batteries,
from an external DC supply, or from an AC line
supply.
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