64 eedm504 d

2

Training

for

Digital Multi-Meter (DMM)

or

Digital Volt Ohm Meter (DVOM)

3© 2009 Snap-on Incorporated; All Rights Reserved 3

Course Objectives• This module covers:

– Digital Multi Meter (DMM) basic sections & use

– Push-buttons terms and uses

– Display readings and symbol locations

– Rotary Dial function symbol definitions

– Terminal test lead symbols and hook ups

– Basic applications

44

Completed Course Outcome• When you complete this module, you will understand:

– settings on the meter

– meter display readings

– importance of proper terminal connections

– basic electrical testing with the meter


5

Digital Multi Meter - Introduction

What do DMMs do for us?

• Converts Electrical Signals to Understandable Values

• Perform highly accurate measurements

• Assist in electrical equation calculations

• Enable testing of sensitive circuits

5© 2009 Snap-on Incorporated; All Rights Reserved

6

Digital Multi Meter - Introduction (con’t)

DMM’s Convert Electrical Signals to Understandable Values

– Converts 2 Types of Electrical Signals

– Rapid electrical pulse conditions • Hard to see - display changes too quickly

– Utilize Min/Max function to help capture data

– Steady state conditions• Slow changing or constant signals


7

DMM’s Perform Highly Accurate Measurements

• digital devices are very accurate

– capture tiny units of measurement

• analog meters (needle reading displays) are not as accurate

– reading based on individual’s subjective view

– cannot display these tiny measurements

7



8


DMM’s Assist in Electrical Equation Calculations

• Ohm’s law equation E (voltage) = I (current) x R (resistance)

– Dial settings select one or more equation elements

– Display value helps to solve for a missing value


9

DMM’s Work Safely on Sensitive Circuits

• High Impedance (or high resistance)

Impedance Definition = opposition to the flow of current

– Minimizes draw from a device or circuit being tested

– Reduces the chance computer circuitry damage

9



10

Digital Multi Meter - Basics

• Four Basic Sections

10

Digital Display

Push-button Functions

Rotary Dial Function Selector

Test Lead Terminals


11

Digital Multi Meter - Display• Digital Display Readings and Locations on Start-up

11

Voltage Type AC or DC

Low Battery - symbol will appear only when power is low

Auto Range/Manual Range

Analog Bar Graph Display of the Selected Value

Auto Power Off

Dial Setting Icon Reference Area

Auto Ranging on Start-up


12

Auto/Manual Range Display

12

• Important to Understand 2 Range Options – Auto Range

– Manual Range

Auto Ranging Manual Ranging


13

Digital Multi Meter – Auto Range Display

© 2008 Snap-on Incorporated; All Rights Reserved 13

AUTO Ranging

Auto Ranging Displayed on Start-up

• Auto Ranging Auto Ranging Advantages

• activated on start-up

• moves decimal automatically

• good for slow changing signals

display location - AUTO symbol

Auto Ranging Disadvantages

• can set improper range

• over-ranging signal requires adjustment


14

Digital Multi Meter – Manual Range Display

14

Manual Ranging

Manual Range Activated via RANGE Button

• Manual RangeManual Range Advantages

• RANGE activated on demand

• moves decimal point on display

• stabilizes rapidly changing signals

• can convert OL readings to values

▪Manual Ranging Button

• Press until desired decimal value is reached

▪

display location - no symbol

Manual Range Disadvantages

• operator must understand and determine proper range


15

Digital Multi Meter – Push-buttons• DMM Push-buttons Features Enhance Dial Functions

15

HOLD freezes a value on the display - second press removes the hold

going back to a live value

RANGE toggles between Auto Ranging or

Manual Ranging

AC/DC toggles between

AC (Alternating Current) or

DC (Direct Current)

Continuity Buzzer - checks circuits for opens, shorts, broken wires loose fuses, etc.

Diode - tests diodes, LED’s etc.

REC activates recording of MIN (minimum) and

MAX (maximum) values

Hz/DUTY toggles between Hertz (Frequency)

or Duty Cycle on ACV, ACA, or Hz

REL activates Relative Mode - sets display to zero - factors out undesired readings


16

Digital Multi Meter – Rotary Dial

16

• DMM Rotary Dial Symbol Definitions

Ohms (or resistance) toggle to Continuity

or Diode Test

AC or DC selectable milliVolts

AC Volts

OFF meter is not active

DC Volts

40 micro amps max. current setting -

measures tiny current draw in DC

CAPACITANCE measures start up

capacitors

HERTZ frequency measurements

4000 micro amps max. current setting selectable AC or DC for very low

current draw

400 milli Amp max. current setting selectable

AC or DC for low current draw

10 Amp max. current setting selectable AC or DC


17

Digital Multi Meter - Terminals

17

• DMM - Test Lead Terminal Symbols

Amps red lead connection 10 Amp fused terminal

micro& milli Amps red lead connection 400 milli

Amp ½ amp fused terminal

COMMON black lead

connection used for most measurements

Volts/OHMS/Hertz red lead

connection used for Voltage, OHMS(resistance)

Diode Test, Continuity, Hertz (frequency) and

Capacitance


18

1. What do the abbreviations DMM and DVOM mean?

2. What are the 4 main sections of a Digital Multi-Meter ?

3. What are two types of ranging?

4. How do the button functions expand the meter capabilities

5. What is the function of the rotary dial?

6. How many test lead terminal ports are there?

Review for Understanding


19

Digital Multi Meter – Set-up & Use• Using Our New Knowledge of:

• Display Readings and Locations• Push Button Features• Rotary Dial Symbol Definitions• Test Lead Terminal Symbols

» We Can Move on to

» Button Functions


20

Digital Multi Meter – Button Functions

20

Button Functions Enhance the Dial Settings• Change from Auto to Manual Ranging

• Record Readings

• Enable Frequency or Duty Cycle

• Filter or Zero Out Input

• Convert from AC to DC readings

• Allow Continuity or Diode Functions

• Hold an important reading


21

Digital Multi Meter – RANGE Button

RANGE

21

• Changes Meter from Auto-Ranging to Manual-Ranging

• Moves Decimal Point for Improved Reading

• Good for rapidly changing signals

• Adjusts Over Loaded (OL) signals to be readable values


2222

Use with Rotary Dial Settings

RANGE

RANGE Button


23

Digital Multi Meter – RECORD Button

REC

23

• Record captures two extreme readings

• MAX - top or maximum reading

• MIN - low or minimum reading

• Use for Rapidly Changing signals

• Starter draw, voltage drop, etc.

• Used with Rotary dial Settings


2424


REC

RECORD Button


25

Digital Multi Meter – Hz/DUTY Cycle Button

Hz/Duty

25

• Check Frequency or HERTZ (Hz)

• How many times per second a signal happens

• simple 8 cycles per second example

• Check Duty Cycle (%)

• Percent of time signal is on

• simple example of duty cycle


2626


Hz/Duty

Hz/DUTY Cycle Button


27

Digital Multi Meter – REL Relative Button

REL

27

• Factors Out Lead Resistance on Sensitive Readings

• Zero’s the display if desired


2828


REL

REL Relative Button


29

Digital Multi Meter – AC/DC Button

AC/DC

29

• Changes from Direct to Alternating Current Settings


3030


AC/DC

AC/DC Button


31

Digital Multi Meter – Continuity/Diode Button

31

• Adds 2 Functions to Ω (Ohms) Setting

• Continuity

• tests circuits for breaks or loose circuit connections

• Diode Testing

• tests electronic components such as diodes, LED’s etc.

/


3232

Use with Rotary Dial Setting

/

Continuity/Diode Button


33

Digital Multi Meter – Data HOLD Button

HOLD

33

• Locks in Reading

• Allows Display to go back to Live Reading


3434


HOLD

Data HOLD Button


35

1. What display symbol does the RANGE button change?

2. What are the two display terms the RECORD button displays?

3. What does the Ω symbol represent?

4. What does the symbol represent?

5. What does the symbol represent?

6. HOLD button freezes reading. How do you get back to a live reading?



36

Digital Multi Meter – Set-up & Use• Moving on to:

• Testing the Test Leads

• Testing Fuses

• Meter Set-up with Simulator Board

• Rotary Dial Settings

• Actual Reading


37

Diode Setting - Test Lead Safety Test

37

• Always Test for Good Leads Before Using a Meter1. Insert red lead into VΩHz terminal

2. Insert black lead into COM terminal

3. Rotate the Dial setting to Ω (Ohms)

4. Press the / Continuity/Diode button once

5. Use the alligator clips. Clip red & black lead together

6. Sound signal means leads should be good

7. Move wires around – intermittent sound could mean broken wires


3838

• Always Test for Good Fuses Before Using a Meter1. Put the red lead terminal into the VΩHz terminal – no black lead

2. Move the Rotary Dial to Ω (Ohms)

3. Press the / button twice to Diode test

4. Remove protective tips from the prod ends

5. Touch the red lead to metal inside the & terminals – Any numeric value including 0.000 indicates good fuse

– Any non-numeric value including OL indicates bad fuse

6. Fuses located in back of meter

A mAµA

Diode Setting - Fuse Safety Test


39

Fuse Replacement

39

• If a Bad Fuse is Detected1. Remove the Protective Boot

2. Turn the Meter with Back Facing Up

3. Unscrew 3 Lower Screws

4. Remove the Protective Cover

5. Locate Bad Fuse • 10A

• .5A

6. Replace with original style fuses

7. Reassemble in reverse order


40

1. Should test leads always be tested before using the meter?

2. Should fuses be tested every time before using the meter?

3. For testing the fuses insert the red lead terminal into which meter terminal?

4. For testing the fuses, after inserting the red lead terminal which two other terminals should the prod end be inserted?

5. What values indicate a good fuse?

6. What values indicate a bad fuse?



41

Signal Generator IntroductionSignal Generator (EESX306A) will be used extensively for tests


42

Signal Generator Introduction

• 5 Main Areas

1. ON/OFF Button a) ON indicator light

2. Battery Terminals

3. Center Switches (2)

4. Center Dials (3)

5. Test Lead Terminal Posts (7)

42

#1 #2 #3 #4 #5 #6

Switches set to

the left

A B C

#7


43

DMM Test Selections

Test Procedure - Outline (most of the following cases)

1. Settings and Terminal Locations

1. Instructions for Conducting the Tests

1. Simulator Board Diagram


44

Digital Multi Meter – DC Volts

44

Display

DC Volts

Rotary Dial

DC VoltsTerminal

VHzBlack lead Red lead


45

Digital Multi Meter – DC Volts Test• Using a 9 volt battery (from the signal generator)

– Connect the red lead to the (+) positive terminal (use alligator clips)

– Connect the black lead to the (–) negative terminal use (alligator clips)

• Refer to the display reading– A reading of 9.0 or above indicates a good battery

– A lower reading indicates a marginal or bad batteryNOTE: If the battery displays low voltage, then, install a good battery (test the

new battery per the above to be sure it has proper voltage)

• Install the battery in the Simulator


46

INSTALL 9 volt

battery

#1 #2 #3 #4 #5 #6

A B C

Switches set to the

left

Dials – black knobs

Test Lead Posts

On/Off button

Signal Generator Now Ready for Tests


47

Digital Multi Meter – AC Volts

Display

AC Volts

47

Rotary Dial

AC VoltsTerminal



48

Digital Multi Meter – AC Volts

• How to run the test

48

• Using the signal generator – ref next slide1. Connect the red test lead to test lead port #5

2. Connect the black test lead to test lead port #6 (ground)

3. Move the Rotary Dial to AC Volts

4. Turn the simulator ON (press on/off button)

5. Rotate the middle dial

6. Watch the meter display for value changes

• This completes the AC Volt Test

B


49

#5 #6

Switches set to the

left

4th Rotate middle

dial (B)

2nd Attach Black

Test Lead (ground)

3rd Push button to ON. Red light goes on. 1st Attach

Red Test Lead

B

Signal Generator Set-up Steps for AC volts


50

Digital Multi Meter – AC millivolts

50

Display

AC milliVolts

Rotary Dial

AC milliVoltsTerminal



51

Digital Multi Meter – AC millivolts

• Test

51

• Using the signal generator1. Connect the red test lead to test lead port #5


3. Move the Rotary Dial to AC/DC milli Volts

4. Press the AC/DC button



7. Watch the meter display for value changes (auto ranges to V)

This Completes the AC milliVolt Test

B


52

#5 #6

Switches set to the

left

4th Rotate middle

dial (B)

2nd Attach Black

Test Lead (ground)


Red Test Lead

B

Signal Generator Set-up Steps for AC milliVolts


53

Digital Multi Meter – DC milliVolts

53

Display

DC milliVolts

Rotary Dial

DC milliVoltsTerminal



54

Digital Multi Meter – DC millivolts

54



3. Move the Rotary Dial to AC/DC milli Volts


5. Rotate the right dial

6. Watch the meter display and bar graph values change

This Completes the DC milliVolt Test

C


55

#4 #6

Switches set to the

left

4th Rotate right dial

(C)

2nd Attach Black

Test Lead (ground)


Red Test Lead

C

Signal Generator Set-up Steps for DC milliVolts


56

Ohms Units of Measure for next demo

56

1. = ohms

– display shows exact resistance in ohms – Example: If 50 is shown on the display = 50 ohms

2. k = kiliohms (ohms x 1,000) – displays k symbol on right side of value

– Example: If 50 k is shown on the display = 50,000 ohms

3. M = megohms (ohms times 1,000,000)– displays M symbol on the right side of value– Example: If 50 M is shown on display = 50,000,000 ohms


57

Digital Multi Meter – Ohms (resistance)

57

Display

Ohms

Rotary Dial Ohms/Continuity//Diode

Terminal



58

Digital Multi Meter – Ohms (resistance)

58

• Using the signal generator1. Remove the 9 volt battery from the signal generator

2. Connect the black test lead to test lead port #6 (use alligator clip)

3. Move the Rotary Dial to Ohms

4. Touch the red test lead to test lead ports #1, #2, #3, #4, #5– Which has the highest resistance?– Which has the lowest resistance– Which indicates an Open Circuit?

This Completes the Ohms Test


59

#1 #2 #4 #6

Switches set to the

left

2nd Attach Black

Test Lead to #6 (ground)

3rd Touch Red Test

Lead to all 5 Test Lead Posts

Signal Generator Set- Ohms (resistance)

#3 #5

1st Remove

9 volt battery


60

Digital Multi Meter – Ω Ohms (resistance)

60

Alternative Ohms Test• Using a fuel injector (not supplied)

1. Connect or insert the red test prod to one terminal

2. Connect the black test prod to the other terminal


4. Watch the meter display values

This Completes the alternative Ω - Ohms Test


61

Digital Multi Meter – Continuity

61

Display

Continuity

Rotary Dial Ohms/Continuity/Diode

Terminal


Press / button once


62


62

• Using the signal generator1. Remove the 9 volt battery from the signal generator 2. Connect the black test lead to test lead port #6 (use alligator clip)

3. Move rotary dial to to Ω (Ohms)

4. Press / button once

5. Touch the red test lead to test lead #7

6. Listen for Continuity buzzer – good circuit

This Completes the Continuity Test


63

#6

Switches set to the

left

2nd Attach Black

Test Lead (ground)

3rd Touch Red Test

Lead to #7 Ground

Signal Generator Set - Continuity

1st Remove

9 volt battery

#7


64


64

Alternative Continuity Test• Using the test leads with alligator clips


2. Press the / Continuity/Diode button once 3. Connect red test to the black test lead (use alligator clips)

4. Listen for continuity buzzer – move the leads around to test for wire breaks

– Buzzer indicates a good circuit – good leads– NO buzzer bad leads or bad circuit

This Completes the Alternative Continuity Test


65

Digital Multi Meter – Diode Test

65

Display Diode

Rotary Dial Ohms/Continuity/Diode

Terminal


Press / button twice


66

Digital Multi Meter – Diode Test

66

• Using a Diode or Diode Simulator (diode not included) 1. Move the Rotary Dial to Ω (Ohms)

2. Press the / Continuity/Diode button twice

3. Touch the red lead to one end of the diode terminal leg

4. Touch the black lead to other end of the diode terminal leg

5. Now reverse the red and black leads on the diode legs

6. OL will show on one test of the diode, a numeric value on the other

7. Good diode - allows flow in one direction only

8. Bad diodes - no reading or numeric reading on both sides

This Completes the Diode Test


67

Digital Multi Meter – DC 40 microAmps

67

Rotary Dial

40µA

Terminal

mAµARed lead Black lead

Display µA

(DC micro Amps only)


68

Digital Multi Meter - DC 40 microAmps

© 2008 Snap-on Incorporated; All Rights Reserved68

• No test on this small unit of measure at this time– Used to test

• Heating flame sensors• Latest micro sensor technology on vehicles

69

Digital Multi Meter – DC 4000+ microAmps

69

Rotary Dial

µA

Terminal


Display µA

Simulator test only – Use


70

Digital Multi Meter – DC 4000+ microAmps

70


2. Re-install battery attaching only the Negative (-) terminal

3. Connect the red test lead to Positive (+) battery terminal

4. Connect the black test lead to Positive (+) battery board terminal

5. Move the Rotary Dial to µA

6. Check the Display Reading – note the decimal position

This Completes the microAmps Test


71

Switches set to the

left

3d Attach Black

Test Lead to + battery board

terminal

1st Attach

Battery to only the (–)

negative terminal

Signal Generator Set-up - DC 4000+ microAmps (µA)

4th Turn Rotary Dial

to µA position and read the

Display

2nd

Attach Red Test Lead to + Battery

Terminal


72

Digital Multi Meter–AC microAmps (4000 micro amps)

72

Rotary Dial

µA

Terminal


Display µA

AC

Press AC/DC button once


73

Digital Multi Meter AC 4000microAmps

73

• No test on this setting at this time


74

Digital Multi Meter – DC milliAmps

74

Rotary Dial

mA

Terminal


Display mA



75

Digital Multi Meter - DC milliAmps (mA)

75


2. Re-install battery attaching only the Negative (-) terminal



5. Move the Rotary Dial to mA


This Completes the milliAmps Test


76

Switches set to the

left

3d Attach Black

Test Lead to + battery terminal

1st Attach


negative terminal

Signal Generator Set-up Steps for DC milliAmps


to milliAmps position and

read the Display

2nd

Attach Red Test

Lead


77

Digital Multi Meter – AC milliAmps

77

Rotary Dial

mA

Terminal


Display mA

AC



78

Digital Multi Meter – AC milliAmps

78



79

Digital Multi Meter – DC Amps

79

Rotary Dial

A

Terminal

ARed lead Black lead

Display A



80

Digital Multi Meter – DC Amps

80


2. Reinstall battery attaching only the Negative (-) terminal



5. Move the Rotary Dial to A


This Completes the DC Amps Test


81

Switches set to the

left

3d Attach Black

Test Lead to + battery terminal

1st Attach


negative terminal

Signal Generator Set-up Steps for DC Amps


to Amps position and

read the Display

2nd

Attach Red Test Lead to + battery

post


82

Digital Multi Meter – AC Amps

82

Rotary Dial

A

Terminal

ARed lead Black lead

Display A



83

Digital Multi Meter – AC Amps

83



84

Digital Multi Meter – Hertz (frequency)

84

Display

Hz -Hertz

Rotary Dial

Hz - Hertz

Terminal



85

Digital Multi Meter – Hertz (frequency)

85



3. Move the Rotary Dial to Hz (Hertz)

4. Turn the simulator on (press on/off button)


6. Watch the meter display for value changes

This Completes the Hertz Test

B


86

#3 #6

Switches set to the

left

#4 Dial Rotate middle

dial (B)

#2 Attach Black Test Lead (ground)

#3 Push button to ON. Red light goes on.

#1 Attach Red Test Lead

B

Signal Generator Set-up for Hertz (Hz)


87

• A capacitor is like a temporary battery– can store electric energy when disconnected from charging circuit

• short term energy storage

– commonly used in electronic devices • maintain power supply while batteries are being changed

• Car audio systems example– stores energy for the amplifier

• sends boosts to speakers when needed

Capacitor – An Energy Storage System


88

Digital Multi Meter – Capacitance Test

88

Display

microfarads

Rotary Dial

or CAP-Capacitance

Terminal


CAUTION: Capacitors store energy - wait at least 5 minutes after power down for the Capacitor to discharge on its own




3. Move the Rotary Dial to or CAP



6. Watch the meter display for change values

This Completes the Capacitance Test

Digital Multi Meter – Capacitance Test

B


#5 #6

Switches set to the

left

#4 Dial Rotate middle

dial (B)

#2 Attach Black Test Lead (ground)

#3 Push button to ON. Red light goes on.

#1 Attach Red Test Lead

B

Signal Generator Set-up - Capacitance


91

Digital Multi Meter – Capacitance

91

Alternative Capacitance Test• Using a Capacitor (not included)

1. Connect the red lead to positive terminal

2. Connect the black lead to negative terminal (if polarity specific)

3. Move the Rotary Dial to or CAP

4. Wait for reading on display

5. Compare display reading to Capacitor value1. Good Capacitor - reading equal to value on capacitor

This Completes the Capacitance Test

-

-

+

-++

+

-


92

1. When testing for AC Voltage which rotary dial setting is used?

2. Another word for Ohms is ______?

3. Good Continuity is signaled by what?

4. What are the 3 steps in setting up the meter to test Amps?

5. A Capacitor is like a mini _______?

6. What two safety tests can you run before using the meter?



93

End of METER Training


64 eedm504 d

Education

digital multi meter

digital display readings

display ac

snapon incorpora

rights reserved13

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range button