Unusual Operating Indications - HP 4262A Operating And Service Manual

Model 4262A
Section III
Table 3-4
Table 3-4. Unusual Operating Indications (Sheet 1of 4).
Indication:
Cause of trouble:
A, Same sample sometimes shows quite
different values between PRL and
SER CIRCUIT MODE measurements,
B. The decimal point moves and measure-
ment unit changes.
A and/or B may occur in the following cases:
Resistance of low loss inductor or
capacitor being measured in R FUNCTION.
Indication:
What to do:
A. Do not set CIRCUIT MODE to AUTO.
Set CIRCUIT MODE to a PRL or SER
setting that shows a valid display.
B. Set LCR RANGE to MANUAL.
Manually settle the instrument
on an appropriate range.
Cause of trouble:
The displayed value fluctuates on minimum
capacitance, maximum inductance or
maximum resistance ranges in either PRL
or SER circuit modes.
Here are some of the reasons why this
happens:
A . A large size sample is being measured,
B . A high voltage power line or similar
exists near the 4262A, .
UNKNOWN
GUARD LroT HroT H CuR
0C Blas = DC BIAS +
D D
i Cx
-.-.",_-..
Metal Case
Lcunr
What to do:
1. Enclose sample in metal case.
Connect case electrically to 4262A
GUARD terminal as illustrated.
2. Use shielded cable for connection
between sample and the instrument.
Connect cable shield to GUARD.,
3-23