Fluke Oscilloscope Calibration User manual

©Fluke 2008 FPM Oscilloscope Calibration Techniques 1
Techniques for Oscilloscope
Calibration
Using either dedicated or multiproduct calibrators
Teleconference:
US & Canada Toll Free Dial-In Number: 1-[phone]
International Dial-In Number:[phone]
Conference Code: 1010759559

©Fluke 2008 FPM Oscilloscope Calibration Techniques 2
Welcome
Greetings from –
Fluke Corporation
Everett, Was ington, USA
We are very pleased to bring you
t is presentation on tec niques for
oscilloscope calibration.

©Fluke 2008 FPM Oscilloscope Calibration Techniques 3
Welcome
T is presentation is based on
Fluke’s extensive experience wit :
– Use and design of calibration
instruments and oscilloscopes
– Our experience and understanding of
t e problems faced w en performing
calibration of oscilloscopes
T anks for your time, we ope you
find it bot valuable and useful.
Welcome and Thanks!

©Fluke 2008 FPM Oscilloscope Calibration Techniques 4
Presented by
Fluke’s Precision Measurement
Business Unit
and Jack Somppi
Electrical Calibration Instruments
Product Line Manager
[email protected]

©Fluke 2008 FPM Oscilloscope Calibration Techniques 5
Fluke Precision
Measurement
Web eminar eries
For information & reservations to
attend our seminars, go to
www.fluke.com, click on t e
sidebar “Events, Seminars &
Training”, and click on FPM Seminar
Series selection,
or directly go to:
www.fluke.com\fpmseminars
Our eminar Topics Include:
•Precision Measurement Tec niques
•Oscilloscope Calibration
•General Metrology
•Temperature Calibration
•Metrology Software
•RF Calibration

©Fluke 2008 FPM Oscilloscope Calibration Techniques 6
Web seminar etiquette
• C oice of Audio – VOIP or Teleconference
–VOIP receives audio only while teleconference
is two way sound
• Don’t mute your p one if you ave background
music enabled
• Use Q&A or c at to send me questions or
request clarification
• T ere will be an opportunity t roug out t e
discussion to pause and ask questions.
• You can view t e material using eit er full
screen or multi window met ods

©Fluke 2008 FPM Oscilloscope Calibration Techniques 7
Techniques for Oscilloscope
Calibration
Using either dedicated or multiproduct calibrators

©Fluke 2008 FPM Oscilloscope Calibration Techniques 8
Objectives for today’s session
• Review t e calibration
requirements of oscilloscopes
• Examine t e basic calibration
tec niques for scope
calibration
• Study scope calibration
instrumentation alternatives
• Consider automation and it’s
benefits
• Identify additional reference
sources for furt er study

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 Simplify oscilloscope calibration
–Allow for full automation
–All signals should be
through single output
–Make procedures available
 Reduce calibration times
 Reduce cost of ownership
–All functions integrated in a single unit
–Allow for upgradeability
(workloadkeeps changing)
–Simplify calibrator support
Benefits with modern scope
calibration

©Fluke 2008 FPM Oscilloscope Calibration Techniques 10
An Introduction to Oscilloscope
Calibration

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Oscilloscope calibration trends
• Perceived as complex
– Modular based calibration systems
– Multiple outputs means many lead c anges
– Hig skill level required
– Time consuming to calibrate
– Automated systems still require manual intervention
• ISO9000 driven manufacturing systems
• Newer measurement functions & accuracy
require formal calibration
• Increasing bandwidt to 1GHz and beyond

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Oscilloscope calibration
workload (The Bandwidth Perspective)
Installed Base (% Units)
Cal’ Workload (% of Base)
20% 40%
<100MHz
55%
<250MHz
30%
90%
>250MHz
15%

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Oscilloscope Architectures
… and what needs to be calibrated

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Timebase with
sawtooth generator
switch
V/cm
+
-
dY dX
R
1
R
2
Trigger
Mode
Level sec/cm
ALT/CHOP
X-Pos
AC/DC
A
B
Ext
Line
AB
Y-Pos
Delay
Analog oscilloscope

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One A/D for each vertical channel
Digital Sampling Scopes use fast
sample and hold with slower A/D.
- no ALT/CHOP mode
- channel skew is a common test
Memory
A
D
A
D
CRT/Display
Ext
Trigger control
Oscillator-
Timebase
Channel 1
Channel 2
µP
Digital storage oscilloscope
(D O)

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Digital phosphor oscilloscope
(DPO)
A
D
Display
Digital
Phosphor
Acquisition
Rasterizer
Display
Memory
µP

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What to calibrate?
•Vertical Channels
–Channel switching
–Deflection range and accuracy
–Bandwidth, pulse response and risetime
•Horizontal Channels
–Timebase accuracy including delay, magnification
and jitter
–Trigger functions
–X-Axis deflection accuracy and X-Y phasing
•Internal calibration signals
•Cursors and measurement readouts
•Z-Axis bandwidth

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 Insure the voltage
amplitude is measured
& displayed properly
Peak-to-
Peak
Voltage
Applied
Pulse
a
Voltage
Applied
DC
DC
Voltage
0V
a
Vertical channel accuracy

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typical frequency 1kHz
Input coupling DC
Any internal 50Ω
ΩΩ
Ω
setting also calibrated
measurement
function V
pp
Number of measurements for averaging
DSO
analog & DSO
Trigger level 50%
Vertical channels verification

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 Insure all measurable
frequencies respond
properly
100%
100%
Vertical channel bandwidth