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SECTION IV
Model 4277A
1) Standard Capacitors
The
HP
16380A Series Standard Capacitors, featuring the four terminal pair
configuration, are recommended for use as performance test standards.
The four
standard capacitors, 16381A (IpF),
16382A (lOpF), 16383A (lOOpF) and 16384A
(lOOOpF) are calibrated at 0.01% accuracy at IkHz (and have capacitances within
0.1% of their nominal values).
For values up to lOMHz, an extrapolation of the
calibrated values at IkHz is used. This is based on the careful consideration of their
inherent residual parameter values and on the actual test measurement to verify the
frequency dependency of the values. Capacitance values at frequencies up to lOMHz
are read from the graph given on the data sheet of each standard.
Note
A
high
capacitance
standard,
useable
in
high
frequency
region,
is
unavailable.
This is because a lOpF capacitor, for example, has a low
impedance value of 0.16Q at lOOkHz. A capacitance standard would have, in
addition, residual impedance which could not be disregarded when compared
to the pure impedance of 0.16Q. Thus, an attempt to conduct tests which
would use the standard capacitor at the higher operating frequency ranges is
not practicable.
2) Standard Resistors
The standard resistors used for accuracy checks should be nearly pure resistances and
should maintain an extremely low residual reactance at frequencies to IMHz. The
HP 16074A Standard Resistor Set, especially designed as standards useable over a
broad frequency region, with thin film resistors and four terminal pair configurations,
is suitable for the accuracy checks. Because of low residual inductance and less skin
effect of the thin film resistors, the 16074A provides the standard resistance values
of 0^1, O.m, IQ and lOQ at ±10% and lOOQ, IkQ, lOkQ and lOOkQat ±0.01% calibration
accuracies to lOMHz (IMHz at lOOkQ).
Open (OS) and Short terminations, which
facilitate optimum zero offset adjustment, and two quasi-inductors are included in
the 16074A.
Note
The OQandlOQ resistors are used as the (pure resistance) reference device in
the Phase Accuracy Test. The O.IQ, IQ and the quasi-inductors are not used
in the 4277A performance tests.
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