HP 4262A User Manual

Section III
Table 3-4
Model 4262A
Table 3-4. Unusual Operating Indications (Sheet 2 of 4).
Indication: Cause of trouble:
When measuring a low impedance (small
inductance, resistance or high capacitance),
measurement error is excessive,
1. Excessive residual impedance (inductance,
capacitance or resistance) of test leads
in a two terminal measurement.
2. Mutual test leaa induction between
current
leads
(Hcur
and
Lcyr)
and
potential
leads
(Hpor
and
Lpor).
Indication:
What to do:
Use test leads in four-~terminal con-
figuration and measure.
Twist current leads (Hcyr and Lcyg) together.
Do the same with potential leads (Hpor and
Lpor).
Additional error is presented as
02LrCx X 100 (%) for C measurement,
where:
w = 27'l'f
f test frequency
Lr = residual inductance
Cx = unknown capacitance
Cause of trouble:
Measurement error is excessive when high
impedance (high inductance, small
capacitance) is measured.
Measurement Cause of error
High Inductance | Stray capacitance
between High and Low
leads.
Small Stray capacitance
Capacitance between High and Low
leads.
What to do:
Use shielded cable for connection
between sample and 4262A UNKNOWN
terminals. Connect outer conductor
to GUARD terminal,
Adjust C ZERO ADJ control properly to
compensate for stray capacitance.
3-24

HP 4262A Specifications

General

Brand	HP
Model	4262A
Category	Measuring Instruments
Language	English