HP 4262A Operating And Service Manual page 56

Table 3-4. Unusual Operating Indications (Sheet 3 of 4).
Indication: Cause of trouble:
Cause A.
Effect of Low terminal capacitance with
respect to ground.
Excessive measurement error.
Sometimes the measurement can not be
Measurement Allowable Stray performed when a relatively large capacitance
Frequency Capacitance Magnitude between Lpor terminal and ground exists,
Allowable magnitudes for stray capacitance
120Hz 100nF without additional error are given in figure at
10kHz 200pF Cause B . . . .
Effect of High terminal capacitance with
UNKNOWN respect to ground. The stray capacitance
cvarp
o .
will reduce test signal level applied to the
Cur POT HpOT Hcur oc s - oC 1S+ sample measured during capacitance
measurement. This decrease in signal level
will not produce an additional error even
when measurement signal level is reduced to
N
a third of its nominal level. It is neccessary,
of course, that special care be taken to use
Re AN the proper test signal level when a device is
H d whose parameters may be affected
L Sample measured w h o s e p y ¢
T p :'L. by the test signal level. Display fluctuations
{7 {7 may sometimes appear.
Indication: What to do:
Internal resistance of a battery can not be
1. Connect
sample battery (observe polarity)
measured. . as illustrated.
2. Batteries up to 40V are measured under
no load conditions,
UNKNOWN 3. If battery voltage exceeds 4V, set
GUARD LcunDcmAsL_Pov HeoT DCBIAS'HCUR DC BIAS to EXT
4, Since the internal resistance of a battery
is relatively low,use the four- terminal
measurement configuration.
Battery
-
3-25