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8508A
Service Manual
3-18
Resistance Calibration
When calibrating the resistance function, each of the resistance modes (Normal, LoI,
Tru
Ω
, Tru
Ω
LoI and HiV
Ω
) must be individually calibrated. The following procedure
assumes use of a multifunction calibrator and calibrates each resistance mode in turn,
range by range. If individual standard resistors are used it may be more convenient to
calibrate all the modes in turn for each resistance value to avoid connecting the same
resistance standard several times during the calibration sequence. A 1 G
Ω
standard
resistor provided in the 8508A-7000K calibration kit is used for ranges above 200 M
Ω
as
the highest resistance available from the 5720A calibrator is 100 M
Ω
. Refer to Table 3-5
for the resistance calibration points and sequence.
Table 3-5. Resistance Calibration Points and Sequence
8508A Range
Modes
Point
Resistance
Zero
0
Ω
2
Ω
Normal, Normal LoI,
Tru
Ω
, Tru
Ω
LoI
Range Gain
1
Ω
Zero 0
Ω
20
Ω
Normal, Normal LoI,
Tru
Ω
, Tru
Ω
LoI
Range Gain
10
Ω
Zero
0
Ω
200
Ω
Normal, Normal LoI,
Tru
Ω
, Tru
Ω
LoI
Range Gain
100
Ω
Zero 0
Ω
2 k
Ω
Normal, Normal LoI,
Tru
Ω
, Tru
Ω
LoI
Range Gain
1 k
Ω
Zero
0
Ω
20 k
Ω
Normal, Normal LoI,
Tru
Ω
, Tru
Ω
LoI
Range Gain
10 k
Ω
Zero 0
Ω
200 k
Ω
Normal, Normal LoI
Range Gain
100 k
Ω
Zero
0
Ω
2 M
Ω
Normal, Normal LoI
Range Gain
1 M
Ω
Zero
0
Ω
20 M
Ω
Normal, Normal LoI,
HiV
Ω
Range Gain
10 M
Ω
Zero 0
Ω
200 M
Ω
Normal, Normal LoI,
HiV
Ω
Range Gain
100 M
Ω
Zero
0
Ω
2 G
Ω
Normal, Normal LoI,
HiV
Ω
Range Gain
1 G
Ω
Zero 0
Ω
20 G
Ω
HiV
Ω
Range Gain
Optional
[1]
[1]
20 G
Ω
range gain is calibrated automatically during 2 G
Ω
HiV
Ω
range gain cal, but may be calibrated separately
(after 2 G
Ω
HiV
Ω
range cal) at 10 G
Ω
if a standard is available. The 100 M
Ω
and 2 G
Ω
Normal
Ω
ranges must be
calibrated before 2 G
Ω
HiV
Ω
range gain point.
Summary of Contents for 8508A
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