Fluke 9500B - Using the 9500 B Time Markers Function to Calibrate the Time Base of a UUT Oscilloscope; Introduction

4.8-4 Section 4: Using the Model 9500B — Time Markers Function
Final Width = 215mm
Descriptions assume 9500B/1100
4.8.5.1 Introduction
Two types of procedures for time base
calibration are given:
a. Using the 9500B as a fixed source, where
the oscilloscope can be adjusted or a
measurement can be taken;
b. Using the 9500B as an adjustable source,
reading oscilloscope deviations via the
9500B screen.
4.8.5.2 Interconnections
a. Use an active head to connect from the
required 9500B channel output to the input
of the UUT Signal Channel to be calibrated.
b. If a trigger is required, use an active head
(or trigger cable) to connect from the
required 9500B channel output to the input
of the UUT Trigger for the Channel to be
calibrated.
4.8.5.3 Common Setup
The following procedures assume that the
9500B instrument is in Manual Mode. It is also
assumed that the user will be familiar with the
methods of editing screen values. In the case
of difficulty, re-read the paragraphs earlier in
this Section 4.
9500B and UUT Oscilloscope Setup
1. Preparation
Ensure that both instruments are powered ON
and warmed up.
2. UUT 'Scope
Select the required function for time base
calibration.
3. 9500B
Ensure that the 9500B is in Time Markers
Function with Output OFF. If in any other
function, press the
key at the right of
the front panel.
4.8.5.4
UUT Scope — Time Base Calibration
using the 9500B as a Fixed Source
Sequence of Operations
Refer to the table or list of UUT Scope time
base calibration points in the UUT Oscilloscope
Manufacturer's Calibration Guide.
Follow the sequence of calibration stages as
directed by the guide, and carry out the
following operations (1) to (6) at each stage.
1. 9500B
Use the front panel controls to set the 9500B
output to the required channel, expected load
impedance, trigger channel, waveshape, period
and p-p voltage for the UUT 'Scope time base
cal point:
2. UUT 'Scope
a. Select the correct channel for the cal point.
b. Select the correct time base speed for the
cal point.
c. Select the correct amplitude range for the
cal point.
3. 9500B Set Output ON.
4. UUT 'Scope
a. Adjust the sweep speed and trigger level
for a stated display.
b. Observe and note the accuracy of marker
alignment, indicating any misadjustment
in the UUT's time base speed or linearity.
5. Calibration
a. If calibration adjustments for time base
speed and linearity are provided, adjust the
UUT's time base to be appropriate to the
settings on the 9500B screen, as detailed in
the UUT Oscilloscope Manufacturer's
Calibration Guide.
b. If no adjustment is provided on the UUT
'Scope, record the timebase condition at
the calibration point as detailed in the UUT
Oscilloscope Manufacturer's Calibration
Guide.
6. 9500B Set Output OFF.
4.8.5.5
UUT Scope — Time Base Calibration,
the 9500B as an Adjustable Source
Sequence of Operations
Refer to the table or list of UUT Scope time
base calibration points in the UUT Oscilloscope
Manufacturer's Calibration Guide.
Follow the sequence of calibration stages as
directed by the guide, and carry out the
following operations (1) to (6) at each stage.
1
. 9500B
Use the front panel controls to set the 9500B
output to the required channel, expected load
impedance, trigger channel, waveshape, period
and p-p voltage for the UUT 'Scope time base
cal point:
2. UUT 'Scope
a. Select the correct channel for the cal point.
b. Select the correct time base speed for the
cal point.
c. Select the correct amplitude range for the
cal point.
3. 9500B Set Output ON.
4. UUT 'Scope
a. Adjust the sweep speed and trigger level
for a stated display.
b. Observe and note the accuracy of marker
alignment, indicating any misadjustment
in the UUT's time base speed or linearity.
5. Calibration
a. Use the 9500B Deviation control to slew
the 9500B Output period/frequency until
the UUT's alignment is appropriate to the
9500B settings, as detailed in the UUT
Scope Manufacturer's Calibration Guide.
b. Record the 9500B screen output voltage
and period/frequency as detailed in the
UUT Oscilloscope Manufacturer's
Calibration Guide.
6. 9500B Set Output OFF.
4.8.5 Using the 9500B Time Markers Function to Calibrate the Time Base of a UUT Oscilloscope