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HVACR317 - Refrigeration

Meters

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Electrical Multimeter Test Instruments

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Analog and Digital Meters

• VOM multimeters measure resistance, voltage, current

Analog Meter

Digital Meter

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Voltage Measurement

• To measure voltage: set the leads, position the selector, and set the range. ALWAYS measure voltage across the load or the source.

W

VOLTMETER

VOLTMETER

LT-1

9 VDC

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Voltage Measurement

• To measure voltage: set the leads, position the selector, and set the range. ALWAYS measure voltage across the load or the source.

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Resistance Measurement

• To Measure resistance: set the leads, position the selector, and set the range. ALWAYS measure resistance across the load, DISCONNECTED from the power source.

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Resistance Measurement

• ALWAYS measure resistance across the load, DISCONNECTED from the power source.

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Current Measurement

• To measure current: set the leads, position the selector, and set the range. Measure current in series, with the load CONNECTED to the power source.

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Current Measurement

• ALWAYS measure current in series with the load CONNECTED to the power source.

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Clamp-on Amp Meters

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Clamp-on Amp Meters

• Clamp around the conductor

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Motor Winding Measurement

• Megohmmeters (“Meggers”) measure motor windings.