Different Functions Of Digital Multi-meter (DMM)

8/13/2019 Different Functions Of Digital Multi-meter (DMM)

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Experiment 01

Objective:To Study The Different Functions Of Digital Multi-meter (DMM)

Apparatus:Digital Multi-meter (DMM)

Probe (leads, wires)

Theory:A multimeter or a multitester, also known as a OM (olt-Ohm meter), is an electronic

measuring instrument that com!ines se"eral measurement functions in one unit# A ty$ical

multimeter may include features such as the a!ility to measure "oltage,currentand resistance

Ty$es of Multimeters%

There are two !asic ty$es of multimeter

Analog meter%

Digital multimeter%
http://en.wikipedia.org/wiki/Electronicshttp://en.wikipedia.org/wiki/Measuring_instrumenthttp://en.wikipedia.org/wiki/Voltagehttp://en.wikipedia.org/wiki/Electric_currenthttp://en.wikipedia.org/wiki/Electric_currenthttp://en.wikipedia.org/wiki/Electrical_resistancehttp://en.wikipedia.org/wiki/Measuring_instrumenthttp://en.wikipedia.org/wiki/Voltagehttp://en.wikipedia.org/wiki/Electric_currenthttp://en.wikipedia.org/wiki/Electrical_resistancehttp://en.wikipedia.org/wiki/Electronics


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Functions Of DMM:

An DMM can measures current#

An DMM can measures the $otential difference ("oltage) !etween two $oints,#

An DMM can measures resistance

An DMM can measure &ontinuity

DMM can measure tem$erature

Multimeter as a Ammeter:

Turn 'ower Off !efore connecting

reak &ircuit

'lace multimeter in series with circuit

Select highest current setting, turn $ower on, and work your way down#

Turn $ower off

Disconnect multimeter#

econnect &ircuit

DMM for Voltage Measuring:

To use a multimeter as a "oltmeter it is connected in $arallel !etween the two $oints where the

measurement is to !e made#

'rocedure for measuring "olts%

*# First determine whether the a$$lying "oltage is A& or D& "oltage#+# Then set the dial to the a$$ro$riate function%

for A& "oltage or for D& "oltage#

# Then testing "oltage set the range to the num!er .ust higher than the e/$ected reading#

0# 'lug your test leads into the $ort $anel #


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DMM used To measure Resistance:

Resistance:

1t is the o$$osition to the flow of currents # and it is measured in ohm#

'rocedure For Testing esistance%

*# To test for resistance, first turn off the powerin the circuit or com$onent you2re testing#

Otherwise you may not get the most accurate reading and damage the DMM#

+# After ensuring that all $ower is off, set the dial to the resistance mode.

# Select the a$$ro$riate rangeon the dial#

0# 'lug in your test leads,connect them to the com$onent under test, and take a reading#

Multimeter as a &ontinuity Tester%

&ontinuity refers to !eing $art of a com$lete or connected whole#1n electrical when an electrical circuitis ca$a!le of conducting current, it

demonstrates electricalcontinuity# 1t is also said to !e 3closed,4 !ecause the circuit is

com$lete# The ohmmeter is a great tool for checking the continuity !etween two $oints#

'rocedure to measure continuity%

The continuity test on a DMM is sim$le#

*# Set the dial to the continuity function#+# 'lug in your lead#

# After ensuring that the $ower is off, make contact with the com$onent under test usingthe leads# The DMM will !ee$ if there is good continuity, or a good $ath that allows current

to flow# 1f there is no continuity, the DMM won2t !ee$#

*# DMM used to measure The &a$acitance%
http://www.wisegeek.com/what-is-an-electrical-circuit.htmhttp://www.wisegeek.com/what-is-an-electrical-circuit.htm


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&a$acitance (sym!ol &) is a measure of a ca$acitor2s a!ility to store charge#

A large ca$acitance means that more charge can !e stored# &a$acitance is measured in farads,

sym!ol F#

5 (micro) means *6-7 8*5F

n (nano) means *6-9 8*nF

$ ($ico) means *6-*+ 8 *$F

To test ca$acitance%

*# Set the dial on the DMM to the ca$acitance function and $lug in your leads#

+# After ensuring that the ca$acitor has !een discharged, connect the test leads to theca$acitor terminals and take a reading# 1f the measurement is similar to the rating listed on

the ca$acitor, the ca$acitor is good#

Precaution: The !lack test lead is always $lug into the &OM .ack#

The red test lead $lug into the .ack and A .ack#

The connection should !e done $ro$erly#

Turn the $ower Off !efore making the connection and after o$erating a function on the

DMM#

Conclusion: A DMM can $erform multi$le function at a time# 1f the connection are loose then the DMM did not gi"e the accurate reading#


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Applications of DMM: oltage Measurements

&urrent Measurements

esistance Measurements

&a$acitance : 1nductance Measurements

Time and Fre;uency

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Different Functions Of Digital Multi-meter (DMM)