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