Introduction to the Digital Multimeter

The most useful tool in electronics

Introduction to the Digital Multimeter

Electronic devices function because of the movement of

invisible electrons

The digital multimeter doesn’t make electrons visible, but it does

tell use what they are doing

The DDM

The DMM Screen

The DMM Function Dial

The Function Dial

Test Leads

What the Basic DMM Measures

• Continuity

• Voltage

• Resistance

• Current

What is Continuity?

Continuity is a complete current path in a circuit.

If there is continuity, electrons can move from the negative terminal of the battery, through

the circuit, and back to the positive terminal of the battery.

Continuity Test

What is Voltage?

Voltage acts like an electrical version of pressure. Voltage pushes electrons through a

closed circuit (one with continuity).

If there is voltage, the electrons flow from the negative terminal of the battery (like charges

repel), though a conducting path, to the positive terminal of the battery (opposite

charges attract).

Voltage Test

What is Resistance?

Resistance acts like a brake on the movement of electrons. While voltage tries to make a greater

number of electrons more move through a closed circuit, resistance tries to keep fewer electrons

moving through the circuit.

If there is the proper amount of resistance in a circuit, electronic components are protected from damage

caused by too many electrons flowing through them.

Resistance Test

What is Current?

Current is the flow of electrons through a closed circuit. Current is work in a circuit, because electrons are being moved from one place to

another.

If there is current in a circuit, then voltage is pushing electrons and resistance is trying to

limit them.

Current Test