The Spruce / Kevin Norris
Amultimeteris a helpful tool for advanced electrical projects.
But multimeter symbols and their meanings can be cryptic to a new user.
The Spruce / Michela Buttignol
What Is a Multimeter?
The Spruce / Kevin Norris
A multimeter is atool that measures electrical propertieslike resistance, voltage, and current.
It is used to test electrical components such as diodes and capacitors.
A multimeter has a dial surrounded by several symbols that identify electrical values.
The Spruce / Michela Buttignol
There are multiple ports for plugging in electrical leads or jacks.
In 1920, British Post Office engineer Donald Macadie invented the multimeter.
Macadie reportedly became frustrated with having to carry around multiple meters and tools.
So, he built a single tool that combined multiple meter functions.
Tip
If you’re just looking to test an electrical receptacle, opt for a voltage tester.
It’s easier to use than a multimeter.
A multimeter can measure bothDC and AC voltages.
Current Symbols
Current is either AC or DC and a multimeter is equipped to measure both.
Resistance Symbols
Multimeters measure resistance by sending an electric current through a circuit.
The resistance is then presented in ohms.
Because different electrical circuits can have vastly different resistances, there are multiple stages of measurement on a multimeter.
To find the continuity test function, look for a symbol that resembles a Wi-Fi symbol on its side.
Diodes are electrical components responsible for converting AC into DC.
Running a diode test will indicate whether or not the diodes are working.
Capacitance Test
Capacitors are electrical components that store a charge.
Testing capacitors can measure the stored charge.
A thermometer symbol will indicate the temperature setting.
On the other end of the thermocouple is a wire attached to a temperature probe.
Multimeter Jacks
To use a multimeter, insert the red and black leads into the appropriate jack.
Most multimeters have three jacks, though some may have four.
A
Place the red lead in theAjack to measure high current up to 10 amps.
This port may also be labeled10A.
mAV
ThemAVjack is used for the red lead when measuring voltage, resistance, and temperature.
On some multimeters, the shift button is called a function button orFn.
Hold
TheHOLDbutton freezes whatever reading is currently on the screen.
This allows you to reference the reading later on.
Manual vs. Auto Range Multimeters
Auto-range multimeters automatically opt for range of the values being tested.
Auto-range multimeters are generally considered to be nearly 100-percent accurate.
Auto-range multimeters are quicker and easier to use than manual multimeters.
