High Performance Oscilloscope Calibrator
Front Panel Base Calibration by Functions
117
6.
If not using the Model 4955, set up external circuitry to measure the appropriate
load resistor (4-wire connection), with the 9500B Active Head output BNC
disconnected.
7.
Set the Standards DMM to the appropriate Resistance measurement range, take a
Resistance measurement and note the result.
Note
Make sure to allow for any settling time of the external measuring
instrument.
8.
If using the Model 4955 Calibration Adaptor:
a.
Set the Model 4955 Calibration Adaptor switch as shown in Table 25.
b.
Reconnect the Active Head output BNC to the Model 4955 input.
9.
If not using the Model 4955, disconnect the load resistor from the DMM, and
reconnect it to the 9500B Active Head output BNC.
10.
Press the ON key to turn the 9500B output on.
11.
Set the Target Res to the value measured in operation (7), using the cursor
controls and/or spinwheel.
12.
Press the ACCEPT CALIB key to generate and implement the correction factor.
The Measured Res value will change to the Target Res value, and the adjustment
of the output amplitude at this target is complete.
Note
Omit operation (13) if you do not wish to save the resistance value of this
target calibration point.
13.
Press the SAVE TARGET soft key.
14.
Press the EXIT key to turn the 9500B output off and return to the Target
Selection screen.
15.
Repeat steps (2) to (14) for each of the target values displayed on the Target
Selection screen (also see Table 25 below).
Note
If other functions are being calibrated in addition to Square Waveform,
refer to Table 18 for information on sequencing calibrations.
Table 25. Load Resistance Measurement Function; Calibration Targets
Function Target
No
Target Resistance
4955 Switch Positions
Default
Minimum
Maximum
Op. 5 (b)
Op. 8 (a)
Θ
1
50.000
Ω
45.000
Ω
55.000
Ω
Ref
50
Ω
Meas
50
Ω
2 50.000
k
Ω
45.000
k
Ω
55.000
k
Ω
Ref 50 k
Ω
Meas 50 k
Ω
3 1.0000
M
Ω
0.9000
M
Ω
1.1000
M
Ω
Ref 1 M
Ω
Meas 1 M
Ω
4 19.000
M
Ω
18.000
M
Ω
19.900
M
Ω
Ref 19 M
Ω
Meas 19 M
Ω
