how to use multi meter

8/3/2019 How to Use Multi Meter

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WORK SHEET Page 1 of 9 DEPARTMENT : ADVANCE SKILL TRAININGSECTION : AUTOMOTIVEMODULE: AUTOMOTIVE ELECTRICAL AND ELECTRONIC SYSTEMCOURSE: BODY ELECTRICALBLOCK: FUNDAMENTAL OF AUTO ELECTRICITY CODE NO :UNITS : ELECTRICAL DIAGNOSIS TOOLS

TITLE : HOW TO USE MULTIMETER

PURPOSE :

THE CENTRE FOR INSTRUCTORANDADVANCED SKILL TRAININGSHAH ALAM, SELANGOR DARUL EHSANMALAYSIA.

MS 1SO 9001


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Page 2 of 9Code No. Worksheet No.

MEASURING VOLTAGE

How the voltage is measured ?

Make the circuit shown in the illustration below, connecting L-1, L-2 and R-1 with lead wires.

1 . Measure the voltages V 1 V 6 using a circuit tester.


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HOW TO MEASURE THE VOLTAGE

1. Connect the red test lead to the positive terminal of the tester, and the black test lead to thenegative terminal of the tester.

2. Select the appropriate range so that the expected maximum voltage can be measured.

NOTE -

All Toyota vehicles use a direct current (DC) power supply, so be sure to set theselector to the DCV range.

3. Connect the test leads to the load in parallel. In this instance, make the connection so thatthe current flows from the positive test probe (red) to the negative test probe (black). Thismeans that the positive test probe is closer to the positive terminal of the power source, andthe negative test probe is farther from it.

- NOTE -

Since a voltmeter has a very large internal resistance, it will not measure the voltage correctly if it is connected in series to the power source.

4. Read the value of the voltage on the appropriate scale.


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5. MEASURING CURRENT

How the current is measured ?

Make the circuit shown in the illustration below, connecting L-1, L-2 and R-1 with lead wires.

1. Measure the amount of current (A 1- A7) using a circuit tester.


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HOW TO MEASURE THE CURRENT

1. Select the appropriate range of the direct-current (DC A) to be measured (First select thehighest range, then adjust the selector to the appropriate range.)If the tester has DC A terminals for two or more ranges, connect the test lead wires to thecorrect terminals

2. Break the circuit to be measured, then connect the tester between those two terminals.This means that the tester must be connected in series to the electric source and loads.In this instance, make the connection so that the current flows from the positive test probe

(red) to the negative test probe (black). (Positive test probe is closer to the positive terminal of the power source, and the negative test probe is farther from it.)

3. Read the scale corresponding to the selected range.


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6. MEANSURING RESISTANCE

How the resistance is measured ?

Measure the resistances of each resistor (R-1 - R-5) and of each lamp (L-1 - L-3).


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HOW TO MEASURE THE RESISTANCE

1. Connect the test leads to the tester and bring the two probes into contact with each other and adjust the calibrating switch until the needle indicates 0 .

2. Select the appropriate range.

Note that the marked divisions on the scale is not even, but become closer together as theresistance increases.Therefore, when is necessary to measure the resistance more precisely, select the range sothat the needle moves within the right from the center of the scale.

3. Disconnect the load to be measured, and then connect the test lead to both ends of theload. Either terminal of the tester may be connected to either end of the load - polarity is notimportant.

4.Read the scale corresponding to the selected range.


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Continuity test

A continuity test checks if the circuit (wires, contacts, etc.) inside an electrical device or system is disconnected (open) or connected (closed).

Set the tester on the x 1 resistance range to make a continuity test.

The tester needle moves if there is continuity (it normally indicates a standard value).

If the needle of the tester does not move, there is no continuity ( ohms open circuit).

RESISTOR COLOR CODE

Solid resistors have a color code printed on them which indicates the resistance value.

1. Four-colored Resistor


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2. Five-colored Resistor

how to use multi meter

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