Looking at your multimeter can be confusing, especially with its seemingly intricate symbols. However, don’t be worried. Once you understand the basics, interpreting multimeter symbols is straightforward. These devices offer an affordable means to achieve precise measurements. This post provides a brief yet thorough guide on understanding multimeter symbols, empowering you to tackle your projects effortlessly!
What is Multimeter?
A multimeter is an electronic tool that measures current, voltage, resistance, and sometimes temperature, commonly known as ‘multi-testers’. They come in various types for home use, automotive purposes, and industrial HVAC tools.
The two main types are analog and digital, with both measuring amps, ohms, and volts. Digital versions are preferred today for their enhanced accuracy. Explore more in my guide on Different Parts of Multimeters.
How Can you Read Multimeter Symbols?
Fluke multimeters are usually favored by home users as well as professional electricians. The symbols they use are standard, and these graphical representations will be the focus of this article.
Note: Some multimeter models may have additional yellow symbols around the rotary switch/dial. To access these, press the shift button, similar to a computer keyboard.
Without delay, let’s understand about the key multimeter symbols one by one.
Hold Button:
Typically found in the top left corner of multimeters, this button secures your meter reading after measurement.
This feature is particularly useful for projects where precise measurements are crucial and when working in awkward or dimly lit locations makes it challenging to read the multimeter immediately.
AC Voltage:
Symbolized by a capital “V” with a wavy line above it, resembling a Spanish accent mark. This symbol is used to measure alternating current (AC) voltage.
This setting is commonly used for electronic measurements of alternating current machines, like kettles, fans, Christmas lights, and televisions. It indicates the voltage of your equipment or mains supply.
Shift: Hz:
The shifted reading above AC Voltage marked “Hz” indicates the frequency of your circuit or equipment. Press the shift button to access this function, similar to a computer keyboard.
DC Voltage:
Represented by a capital “V” with three hyphens (—) and a single straight line on top, resembling a V with a road drawing. This symbol is for measuring direct current (DC) voltage.
This is the setting for measuring smaller circuits powered by direct current, like batteries, cells, and indicator lights.
Continuity:
Depicted as a row of closed-end parentheses, similar to the sound symbol. This button is used to test the continuity of a circuit.
Resembling a row of expanding closed-end parentheses, this symbol is akin to the sound icon in PCs and apps. The multimeter emits an audible beep when detecting a complete circuit, offering a simple and effective method to check for connection issues in electrical tools and toys.
Direct Current:
Resembles an “A” with three hyphens (—) and a single line on top. This symbol is for measuring direct current (DC) in amps.
Current Jack:
Identified by a red jack with an “A” above it, designated for measuring currents with clamp attachments or a red lead.
To avoid damaging your multimeter’s internal fuse when uncertain about the approximate current, start with this port.
Common Jack:
A black jack with “COM” above it, located centrally between two black jacks. It is suitable for all measurements but should be used with black test leads.
Range Button:
Positioned across the top of the multimeter with a “Lo/Hi” symbol above it, facilitating the selection of different meter ranges.
Though many modern multimeters, including the Fluke 117, feature auto-ranging, some models allow manual selection of a specific range, such as switching from ohms to megaohms.
Brightness Indicator:
Functions like on an iPhone, allowing you to adjust screen brightness for easier reading, particularly outdoors.
AC Millivolts:
Denoted by an “mV” with a squiggly line on top, used for testing smaller circuits with low AC voltage.
Switching to millivolts enhances precision and provides a more accurate reading.
Shift DC Millivolts:
Located next to AC Millivolts, it features a “road” symbol (three hyphens with a straight line), serving the same function but with DC voltage. Press the shift button to access this function.
Similar to the AC millivolts function, it’s employed for precise measurements or in circuits with minimal voltage. However, it should be exclusively used on equipment utilizing direct current, such as power from cells and batteries.
Ohms:
Symbolized by the Omega letter, used for obtaining accurate resistance readings and checking blown fuses.
Need more functionality? This button also aids in determining if a fuse has blown. If your meter shows ‘OL,’ it indicates a blown fuse that requires replacement.
Note: Ensure you’ve removed fuses from the circuit when using the ohms setting on your multimeter. Whether solo or in a team, over 100 electricians die annually from electrocution. Safety first!
Diode Test:
Depicted with an arrow pointing right and a plus sign, indicating the status of diodes as good or bad.
It functions by applying a low voltage across the diode and assessing the resulting voltage drop, offering a more precise alternative to testing with the ohms setting.
Shift Capacitance:
The shift option on the Diode Test button, resembling two facing “T” letters, used for measuring capacitance. Press the shift button to access this function.
Alternating Current:
Represented by a capital “A” with a squiggly line above it, akin to Spanish accent marks. This symbol is used to measure alternating current (AC).
Typically requiring a clamp attachment for its functions, this option is an excellent method for examining current loads in AC circuits.
Red Jack:
The other red jack, usually on the right-hand side, with various symbols of measurement above it. It is used for specific measurements depending on the symbols indicated.
Here’s why! The red jack covers nearly everything except current. It’s handy for reading temperature, duty cycle, frequency, resistance, voltage, and more.
Conclusion
That was all about the symbols in a multimeter. If you have any questions make sure to write us in the comments.
