MULTIMETERMULTIMETERMansoor Asif Mansoor Asif

EE 701EE 701

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Scheme of Scheme of presentationpresentation

• Introduction• Parts of Multimeter• Function of each part• Operation • Uses of Multimeter

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IntroductionIntroduction

• Donald Macadie in 1920• Avometer• Analog Multimeter ,Digital

Multimeter or Bench top Multimeter

• AMM ,DMM,BTM• US$10-US$5000• ACWEEC

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IntroductionIntroduction

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Parts of MultimeterParts of Multimeter

• Meter scale (AMM)• Liquid crystal display(DMM/BTM)• Pointer adjust(AMM)• Selector function range• Test probes• Battery

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Parts of MultimeterParts of Multimeter

Test probes

LCD

Selector function range

Pointer adjust

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Parts of MultimeterParts of Multimeter

Analog Multimeter

Meter scale

Selector function range

Common terminalVΩ terminal

Amps terminal

Title

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Function of partsFunction of parts

• Meter scale takes the pointer reading

• LCD shows the reading in digits• Pointer adjust fixes the pointer

position and remove error• Selector function range selects

the quantity we want to measure• Test probes help us connecting to

device we want to test

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Parts of MultimeterParts of Multimeter

Test probes

LCD

Selector function range

OperationOperation

Principle of Multimeter• Electromagnetism • Force on a current carrying

conductor

Working • Select the desired quantity by

selector range• Connect the two needles of probe

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OperationOperation

• τ=NIBAcosα • Deflecting couple =NIBA• Restoring torque=cθ• Deflecting torque=restoring

couple• I=cθ/BAN• “I” depends on “θ” directly

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OperationOperation

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UsesUses

It is used to measure• Voltage in volts.• Current in amperes• Resistance in ohms• Capacitance in farads• Conductance in Siemens• Continuity of circuit

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QUESTIONS?