MULTIMETER USAGE - CONTINUED - TM-5-2410-233-230868

TM 5-2410-233-23

ELECTRICAL GENERAL MAINTENANCE INSTRUCTIONS - CONTINUED

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MULTIMETER USAGE - CONTINUED

(2)

Select OHMS.

(3)

Select lowest VOLTAGE/OHMS range. If test specifies ohms range, select required range.

(4)

Connect black and red probes across circuit to be tested.

(5)

Observe readout and interpret results as circuit resistance.

Voltage Tests.

a. Measuring DC Voltage.

(1)

Set multimeter to ON.

(2)

Select lowest possible DC VOLTAGE range that is still higher than voltage to be measured.

(3)

Connect red probe to positive (+) pin and black probe to negative (-) pin.

(4)

Observe readout and interpret results as DC voltage in circuit being tested.

b. Measuring DC Voltage Drop.

NOTE

Voltage drop is defined as the amount of voltage loss that occurs through all or part of a circuit due to resis-

tance.

(1)

Set multimeter to ON.

(2)

Select lower possible DC VOLTAGE range that is still higher than voltage to be measured.

(3)

Connect red probe to test location closest to positive (+) side. Connect probe to test location closest to

ground.

(4)

Observe readout and interpret results as DC voltage in circuit being tested.

DC Voltage Drop Examples.

Good Voltage Drop.

(1)

(a) Example A shows how to measure voltage drop across a good splice connection. Voltage reading at

multimeter should be low (about 0.1 volt). This means that resistance across this splice is low, result-

ing in low voltage drop.

EXAMPLE A

24 - VOLT

GOOD SPLICE

BATTERY PACK

CONNECTION

SWITCH

LAMP

(CLOSED)

386-593

(b) Example B shows how to measure voltage drop across a closed switch. Voltage reading at multimeter

also should be low (about 0.1 volt). This means that resistance across this switch is low, resulting in

low voltage drop.

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