Extech Instruments MS400 User manual

User Manual
Handheld Digital Storage
Oscilloscope & Multimeter
Model MS400
Figure 1 – Meter Faceplate

MS400 Version 2.0 – December 2007
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Warranty
EXTECH INSTRUMENTS CORPORATION warrants this instrument to be free of
defects in parts and workmanship for one year from date of shipment (a six month
limited warranty applies to sensors and cables). If it should become necessary to return
the instrument for service during or beyond the warranty period, contact the Customer
Service Department at [phone] ext. 210 for authorization or visit our website
www.extech.com for contact information. A Return Authorization (RA) number must be
issued before any product is returned to Extech. The sender is responsible for shipping
charges, freight, insurance and proper packaging to prevent damage in transit. This
warranty does not apply to defects resulting from action of the user such as misuse,
improper wiring, operation outside of specification, improper maintenance or repair, or
unauthorized modification. Extech specifically disclaims any implied warranties or
merchantability or fitness for a specific purpose and will not be liable for any direct,
indirect, incidental or consequential damages. Extech's total liability is limited to repair
or replacement of the product. The warranty set forth above is inclusive and no other
warranty, whether written or oral, is expressed or implied.
Calibration and Repair Services
Extech offers repair and calibration services for the products we sell. Extech also
provides NIST certification for most products. Call the Customer Care Department for
information on calibration services available for this product. Extech recommends that
annual calibrations be performed to verify meter performance and accuracy.

Support line [phone]
Technical Support: Extension 200; E-mail: [email protected]
Repair & Returns: Extension 210; E-mail: rep[email protected]
Product specifications subject to change without notice
For the latest version of this User’s Guide, Software updates, and other
up-to-the-minute product information, visit our website: www.extech.com
Extech Instruments Cor
p
oration
,
285 Bear Hill Rd.
,
Waltham
,
MA 02451

MS400 Version 2.0 – December 2007
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Table of Contents
Chapter Page
Safety Information 5
Safety Terms and Symbols 5
Specific Warning and Caution Terms 5
Terms Used With This Product 5
Symbols Used With This Product 5
General Safety Information 5
General Inspection 7
Performing a General Inspection 7
Checking for Shipping Damage 7
Checking Accessories 7
Complete Instrument Check 7
Contents of the Meter Kit 7
Input Connections 8
Input Connections 8
Description of the Front Panel and Keys 8
Using the Scope 11
About this Chapter 11
Powering-Up the Oscilloscope 11
Oscilloscope Operation Window 11
Navigating a Menu 13
Manually Setting the Vertical System, Horizontal System and Trigger Position 14
Resetting the Oscilloscope 17
Input Connections 17
Displaying an Unknown Signal with Auto Set 18
Automatic Zero-ing of Trigger Horizontal Position and Trigger Level Position 18
Automatic Measurements 18
Freezing the Screen 19
Using Average for Smoothing Waveforms 19
Using ‘Persistence’ to Display Waveforms 20
Using Peak Detection to Display Glitches 20
Selecting AC-coupling 21
Reversing the Polarity of the Displayed Waveform 22
Using Waveform Math Functions 23
Using the Multimeter 24
About this Chapter 24
Meter Connections 24
Multimeter Operation Window 24
Multimeter Measurements 26
Measuring Resistance Values 26
Diode Measurement 26
Continuity Tests 26
Capacitance Measurement 27
DC Voltage Measurement 27
AC Voltage Measurement 27
DC Current Measurement 28
AC Current Measurement 28
Freezing the Readings 29
Taking a Relative Measurement 29
Selecting Automatic/Manual Range Adjustment 30

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Advanced Oscilloscope FUNCTIONS 31
About this Chapter 31
Setting the Vertical CH1 and CH2 31
Setting the Channel Coupling 32
Enabling the Scope Channels 33
Adjusting the Probe Scale 33
Inverting a Waveform 33
Math Function Menu Settings 33
Setting the Trigger System 34
Triggering Control 35
Edge Triggering 35
Video Triggering 36
‘Acquire Mode’ Setting 37
Display Settings 37
Display Style 38
Persistence Mode 38
XY Mode 39
Saving Waveforms 39
Function Setting Menu 40
Automatic Measurements 40
Cursor Measurements 41
System State Menu 43
Setting Time Base Mode 44
Data Transmission – PC Interface 45
Trouble Shooting 46
Appendix 47
Appendix and Specifications 47
Oscilloscope 47
Meter 49
General Specifications 50
Appendix B: Maintenance and Cleaning 51
Common Maintenance 51
Storage of Oscilloscope 51
Replacing the Lithium Battery Unit 51

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Safety Information
Note: Please read this user manual prior to operating the unit.
Safety Terms and Symbols
Specific Warning and Caution terms that appear throughout the manual
Warning: “Warning” identifies conditions and actions that pose hazards to users.
Caution: “Caution” identifies conditions and actions that may damage the product.
Terms printed on the meter and contained in this manual
The following terms may appear on the product or anywhere throughout the associated
manuals:
Danger: The term “Danger” is used in this manual to indicate that serious injury or
death may result if the safety instructions are not followed.
Warning: The term “Warning” is used in this manual to indicate that personal injury may
result if instructions are not followed.
Notice: The term “Notice” is used in this manual to indicate that damages to product,
other properties, or accessories may result if instructions are not followed.
Symbols Used on this Product and in the documentation
The following symbols may be found on the meter and in associated documentation:
General Safety Information
Carefully read the following safety information in order to avoid any personal injury and
damage to this product or to any products associated with its use. In order to lessen the
chances of any possible dangers that may occur in connection with the use of this
product, the product should only be used in the specified applications the product was
designed and intended for.
Warning:
To avoid fire or electrical shock please use the proper power adapter. Use only
the power adapter recommended by the manufacturer.
Warning:
If test tool inputs are connected to more than 42V peak (30Vrms) or used in
circuits of more than 4800VA, adhere to the following guidelines in order to
avoid fire or electrical shock:
● Use only insulated voltage probes, test leads and the adapter supplied with
the test tool, or indicated by Extech as suitable for the Oscilloscope &
Multimeter.
● Before use inspect voltage probes, test leads and accessories for
mechanical damage and replace when required.
● Remove all probes, test leads and accessories that are not in use.
High Voltage Refer to
User Manual
Protective
Ground
Measurement
Ground
Casing
Ground

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● Always connect the power adapter first to the AC outlet before connecting
it to the Oscilloscope & Multimeter.
● Do not apply voltages that differ more than 400V from earth ground to any
input when measuring in a CAT III environment.
● Do not apply voltages that differ more than 400V from earth ground to any
input when measuring in a CAT II environment.
● Do not apply voltages that differ more than 400V from each other to the
isolated input when measuring in a CAT III environment.
● Do not apply voltages that differ more than 400V from each other to the
isolated inputs when measuring in a CAT II environment.
● Do not apply input voltages above the rating of the instrument. Use caution
when using 1:1 test leads because the probe tip voltage will be directly
transmitted to the Oscilloscope & Multimeter.
● Do not use exposed metal BNC or banana plug connectors. Do not insert
metal objects into connectors.
● Always use the Oscilloscope & Multimeter only in the manner specified.
● Voltage ratings that are mentioned in the warning are provided as limits for
“working voltage”. The representative Vac rms (50-60Hz) indicates AC sine
wave applications and as Vdc for DC applications. Overvoltage Category III
refers to distribution level and fixed installation circuits inside a building.
Overvoltage Category II refers to local levels, which are applicable for
appliances and portable equipment.
Only qualified technical personnel should perform maintenance.
Pay attention to the nominal values of all terminals: To avoid fire or electric
shock, please keep a watchful eye on all nominal values and marks specified on
this product. Before any connections are made, carefully read the user’s manual
of the product for further information of nominal values.
DO NOT operate this product without the instrument cover plate in place: If the
cover plate or panel has been removed, do not perform any operations with this
product.
DO NOT come into contact with bare conductors: When the product is powered
on, do not touch any bare joints or parts of the meter.
DO NOT operate this product in case of any undetermined failure: When in
doubt of the cause of any damage to this product, consult qualified technical
personnel.
Keep the product well ventilated: Refer to the user manual for detailed installation
instructions. Make sure the product is operated in a well ventilated area.
DO NOT operate this product in humid conditions.
DO NOT operate this product where explosives are handled or used.
Keep the product surface clean and dry.

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General Inspection
After purchasing a new MS400 oscilloscope, it is suggested that a general inspection of
the instrument be performed according to the following steps:
Check whether there is any damage to the product caused by shipping
If the packing material, boxes or foam cushions are found in a damaged condition, keep
them in a proper place until the complete instrument and accessories have passed
electrical and mechanical tests.
Check the Accessories
Double check the accessory list and pictures of the parts and accessories included with
your instrument. Check whether there is any accessory loss by referencing the Appendix.
In case of any accessory loss, damage or variation in specifications, contact the
organization where the product was purchased.
Check the Instrument
If the instrument is apparently damaged, fails in normal operation or in a performance
test, consult the place of purchase.
If the instrument is damaged due to shipping, keep the packing material in a proper place
and contact the place of purchase.
Contents of the meter kit
Description Standard Optional
Meter ●
Adapter ●
Two (2) Oscilloscope Probes (grey) ●
Pair of Test Leads for Multimeter (black and red) ●
Measuring Extension Module for Low Current ●
Measuring Module for low range Capacitance ●
Adjustment Probe Tool ●
One (1) USB Data Transmission cable ●
User Manual ●
One (1) disk that includes the PC interface
software
●
Carrying Case ●

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Input Connections
Figure 2
Description:
1. AC power adapter for AC power supply and battery recharging
2. Multimeter test leads
3. Multimeter input jacks, including three circular banana jacks and two square jacks.
The three circular jacks are used for voltage, current and resistance inputs, while the
two square jacks are used for capacitance inputs
4. Oscilloscope probes
5. Oscilloscope channel inputs: The upper one is for Channel 1 (CH1) while the lower
one is for Channel 2 (CH2)

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Description of the Front Panel and the Keypad
132
4
8
7
6
9
5
11 14 12 15
20
19
13
18
17
10
16
Figure 3
Description:
1. Power adapter jack
2. Serial port
3. USB jack
4. Backlight switch
5. POWER: Power switch
6. A: Multimeter current measurement key
7. V: Multimeter voltage measurement key
8. R: Multimeter resistance, diode, On/Off and capacitance measurement key
9. OSC LEFT: Oscilloscope left-direction adjustment key
10. OSC RIGHT: Oscilloscope right-direction adjustment key
11. OSC OPTION: Oscilloscope setting key

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Using the four keys OSC LEFT, OSC RIGHT, OSC UP and OSC DOWN, users
can make the following settings by pressing OSC OPTION. The settings include:
Voltage Unit Scale for Channel 1 (CH1 VOL); Voltage Unit Scale for Channel 2
(CH2 VOL); Primary Time base (TIME BASE), zero point position for Channel 1
(CH1 ZERO), zero point position for Channel 2 (CH2 ZERO), trigger horizontal
position (TIME) and trigger level position (TRIG).
When performing Waveform Calculations, users can also adjust and calculate the
Display Multiplying Factor of a Waveform (CHM VOL) and the vertical display
position (CHM ZERO).
In cursor measurement mode, users can adjust the positions of Cursor 1 (V1 or
T1) and Cursor 2 (V2 or T2).
12. OSC DOWN: Oscilloscope display downward adjustment key.
13. OSC UP: Oscilloscope display upward adjustment key.
14. OSC/DMM: Press to switch between oscilloscope and multimeter.
15. AUTO SET:
In the Multimeter Mode, when performing a current or voltage measurement, the
user can switch between AC and DC with this key; when performing a resistance
measurement, the user can select resistance, diode, On/Off or a capacitance
measurement with this key.
This key is used for auto setting in the oscilloscope operation mode.
16. RUN/STOP: key for starting or stopping an operation.
17. MENU DOWN: Move down the menu list.
18. MENU: Show / Hide the menu.
19. MENU UP: Move up the menu list.
20. F1～F5: Switch or Adjustment options for each menu

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Using the Scope
About this Chapter
This chapter provides a step-by-step introduction to the oscilloscope’s functionality. The
introduction does not cover all of the capabilities of the scope functions but gives basic
examples to show how to use the menus and perform basic operations.
Power-Up the Oscilloscope
Connect the oscilloscope to AC power via the power adapter as shown in Figure 2
Turn the oscilloscope on by pressing the power on/off key POW.
The instrument then performs a self-check. A greeting window with “press any key to
continue.” displays after the self-check.
The user can press any key to enter the measurement functions.
The oscilloscope powers up in the last setup configuration.
Oscilloscope Operation Window
Figure 4: Oscilloscope Operation Window

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1. Battery power level indicator symbols, including , , and .
2. Auto measurement window No. 1 where “f” is frequency, “T” is cycle, “V” is the
average value, “Vp” the peak-peak value and “Vk” the root-mean-square value.
3. Auto measurement window No. 2.
4. The pointer indicates the horizontal triggering position.
5. This reading gives the time difference between the horizontal triggering position and
the screen centerline. It reads zero when the pointer is in the center of the screen.
6. The trigger state indicates the following information:
Auto: The oscilloscope is in the automatic mode and displaying the waveform in the
non-trigger mode.
Trig’d: The oscilloscope has detected a trigger and is collecting the information
generated after the trigger.
Ready: All pre-triggered data have been captured and the oscilloscope is ready to
receive trigger signals.
Scan: The oscilloscope can gather/display the waveform data continuously in scan
mode.
Stop: The oscilloscope has stopped collecting the waveform data.
7. The green pointer shows the trigger voltage level.
8. A hidden-style menu: With the MENU key pressed, the user can view or hide the
menu.
9. Menu setting options: Various setting options for available menus.
10. The value of the trigger voltage level.
11. The display shows the trigger signal source.
12. The reading gives the value of the primary time base.
13. These graphics present the coupling modes of channel 2 (CH2). The graphic “～”
indicates AC, the graphic “－” indicates DC.
14. This reading shows the vertical Voltage Unit Scale of CH2.
15. These graphics show the coupling mode of CH1, the graphic “～” expresses and
indicates AC, the graphic “－” indicates DC.
16. This reading shows the vertical Voltage Unit Scale of CH1.
17. The blue pointer gives the grounding data point for the waveform on CH2, which is
the zero position of CH2. If this pointer does not display then the channel has not
been opened.
18. OSC OPTION operation prompt: There are various prompts for the available OSC
OPTION operations.
19. The red pointer gives the grounding data point for the waveform on CH1, which is the
zero position of CH1. No display of this pointer indicates that the channel has not
been opened.
20. Waveform display area. Red waveform represents CH1, blue waveform represents
CH2.

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Navigating a Menu
The following example shows how to use the tool’s menus to select a function, as shown
in figure 5:
1. Press the MENU key to display the Function Menu on the right of the screen and the
corresponding optional settings on the bottom. Press MENU again to hide the
Function Menu.
2. Press the MENU UP or MENU DOWN key to select various function menus.
3. Choose a key from F1 to F5 to change the function setting.
Figure 5: the Tool’s Menus

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Manually Setting the Vertical System, Horizontal System and
Trigger Position
Using the four keys OSC LEFT, OSC RIGHT, OSC UP and OSC DOWN, the user can
make the following settings by pressing OSC OPTION. The settings include: Voltage Unit
Scale for Channel 1 (CH1 VOL), Voltage Unit Scale for Channel 2 (CH2 VOL), Primary
Time base (TIME BASE), zero point position for Channel 1 (CH1 ZERO), zero point
position of channel 2 (CH2 ZERO), trigger horizontal position (TIME) and trigger level
position (TRIG).
The following example shows how to use the OSC OPTION key:
1. Press the OSC OPTION key once; the following is displayed at the bottom left side of
the screen, as shown in figure 6:
LEFT/RIGHT – Time Base
UP/DOWN – CH1 Volts/Div
Figure 6: Voltage Unit Scale of Channel 1
2. Press the key OSC UP or OSC DOWN to adjust the vertical scale of Channel 1 and
press OSC LIFT or OSC RIGHT to adjust the horizontal time scale.
3. Press OSC OPTION once again, the following display is visible at bottom left side of
the screen as shown in figure 7:
LEFT/RIGHT – Time Base
UP/DOWN – CH2 Volts/Div

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Figure 7: Voltage Unit Scale of Channel 2
4. Press the OSC UP or OSC DOWN key to adjust the vertical scale of Channel 2 and
press the OSC LIFT or OSC RIGHT key to adjust the horizontal time scale.
5. Press the OSC OPTION key one more time, and the following display is visible at the
bottom left side of the screen, shown in figure 8.
LEFT/RIGHT – Time
UP/DOWN – CH1 Zero
Figure 8: Zero Point Position of Channel 1
6. Press OSC UP or OSC DOWN key to adjust the zero position of Channel 1 in the
vertical direction and press OSC LIFT or OSC RIGHT key to adjust the horizontal
position.

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7. Again, press OSC OPTION key and the following appears at the bottom left side of
the screen, shown as the following figure 9:
LEFT/RIGHT – Time
UP/DOWN – CH2 Zero
Figure 9: Zero Point Position of Channel 2
8. Press the OSC UP or OSC DOWN key to adjust the zero position of Channel 2 in the
vertical direction and press OSC LEFT or OSC RIGHT key to adjust the horizontal
position.
9. Press OSC OPTION key once more and the following appears at the bottom left of
the screen, shown as the following figure 10:
LEFT/RIGHT – Time
UP/DOWN – Trig
Figure 10: Trigger Level Position
10. Press the OSC UP or OSC DOWN key to adjust the trigger position of Channel 2 and
press OSC LIFT or OSC RIGHT key to adjust the horizontal position.
11. Press the OSC OPTION key again and return back to step 1.

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Term Glossary
Vertical scale factor is the voltage amplitude represented by a division in the vertical
direction of the display area. The user can amplify or attenuate the signal with this
scale factor and thus regulate the signal amplitude for the expected range.
Vertical zero position is referred to as the grounding data point through the
adjustment of which one can regulate the display position of the waveform on the
screen.
Primary time base refers to the time values represented by a division in the
horizontal direction of the display area.
Trigger horizontal position is the time deviation between the actual trigger point
and the screen central line which will be displayed as 0 at the center point of the
screen.
Trigger level position represents the voltage deviation between the actual trigger
level and the zero position of the triggering signal source channel.
Resetting the Oscilloscope
To reset the Oscilloscope to the factory default settings:
1. Press the MENU key. The function menu appears on the right side of the screen
2. Press the MENU UP or MENU DOWN key to select FUNCTION. Three options
will be visible at the bottom of the screen.
3. Press F1 to select Factory Settings. The oscilloscope will revert to the factory
settings.
Figure 11: Reset the Oscilloscope
Input Connections (fig. 2)
Examine the bottom and the right side of the Oscilloscope. The Oscilloscope has seven
signal inputs: two safety BNC jack inputs (CH1 and CH2) for scope measurements, three
safety 4-mm banana jack inputs for Multimeter R, V and A measurements, and two
square jack inputs for Multimeter capacitance measurements.
Isolated inputs allow independent floating measurements between Multimeter and Scope.

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Displaying an Unknown Signal with Auto Set
The Auto-Set feature allows the Oscilloscope to display and measure unknown signals
automatically. This function optimizes the position, range, time-base, and triggering and
assures a stable display of virtually any waveform. This feature is especially useful for
quickly checking multiple signals.
To enable the Auto-Set feature:
1. Connect the test probe to the signals under test.
2. Press the AUTOSET key. The Oscilloscope is now in the automatic measurement
mode. The tested signals appear on the screen.
Automatic Zero-Returning of Trigger Horizontal Position and
Trigger Level Position
When the trigger horizontal position and trigger level position are adjusted to maximum,
they will become positioned off-screen. The following steps will allow the trigger horizontal
position and trigger level position to return to zero automatically:
1. Press the OSC LEFT key and the OSC RIGHT key simultaneously, the trigger
horizontal position automatically returns to zero.
2. Press the OSC UP and the OSC DOWN buttons simultaneously, the trigger level
position automatically returns to zero.
Automatic Measurements
The Oscilloscope offers 5 ranges of automatic scope measurements. Two numeric
readings can be displayed: measurement 1 and measurement 2. These readings are
selectable independently and the measurements can be performed on the input CH1 or
input CH2 waveform.
To choose a frequency for CHI1:
1. Press the MENU key. The function menu appears on the right side of the screen.
2. Press the MENU UP or the MENU DOWN key to select MEAS SET1. Five selectable
items are visible at the bottom of the screen.
3. Press the F1 key and select Freq CH1 from the mean square root value item. The
measurement 1 window turns red in color and shows the frequency for input CH1.
To choose a Peak-Peak measurement for Input CH2:
1. Press the MENU key. The function menu is displayed on the right side of the screen.
2. Press the MENU UP or the MENU DOWN key and select MEAS SET2, with 5
selectable items displayed at the bottom of the screen.
3. Press the F4 key to select PK-PK CH2 from Peak-Peak item. The measurement 2
window turns blue in color and shows the peak-peak value for input CH2.
Figure 12: Automatic Scope Measurements

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Freezing the Screen
1. Press the RUN/STOP key to freeze the screen. STOP appears at top right side of the
screen.
2. Press the RUN/STOP key once more to resume measurement.
Figure 13: Freezing the Screen
Using Average for Smoothing Waveforms
To smooth the Waveform:
1. Press the MENU key and the function menu will appear on the right side of the
screen.
2. Press the MENU UP or the MENU DOWN key to select ACQU mode, with four
selectable items displayed at the bottom of the screen.
3. Press the F3 key to select Average Factors, then, press F4 to jump to Averages. This
averages the outcomes of 4, 16, 64, or 128 acquisitions and shows the final
averaging result on the screen, shown as in the following figures.
Figure 14: Average Factor Sampling Mode

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Using Persistence to Display Waveforms
You can use Persistence to observe dynamic signals:
1. Press the MENU key and the function menu will appear on the right side of the
screen.
2. Press the MENU UP or the MENU DOWN key to select DISP SET. Four selectable
items are displayed at the bottom of the screen.
3. Press the F2 key to select Persist 1 sec, 2 sec, and 5 sec, Infinite or OFF. In this
case, jump to Infinite and the observed dynamic is kept on the screen continuously.
When the item OFF is selected, the Persistence function is switched off.
Figure 15: Using ‘Persistence’ to Observe Dynamic Signals
Using Peak Detection to Display Glitches
The user can use this function to display events (glitches or other asynchronous
waveforms) of 50 ns or wider:
1. Press the MENU key and the function menu will appear at the right side of the
screen.
2. Press the MENU UP or the MENU DOWN key to select the ACQU MODE. Four
selectable items are displayed at the bottom of the screen.
3. Press the F2 key and jump to Peak Detect.
Figure 16: Peak Detection