:max_bytes(150000):strip_icc()/SPR-multimeter-symbols-8414239-hero_92226-947f412324044a5e8a0c4fc9d4be221a.jpg?w=1200&resize=1200,0&ssl=1 "A Complete Guide to Multimeter Symbols")
A multimeter is a useful instrument for superior electrical initiatives. However multimeter symbols and their meanings could be cryptic to a brand new consumer.
Study what multimeter symbols imply, how you can join the jacks within the ports, and some fundamentals about how you can use a multimeter.
The Spruce / Michela Buttignol
What Is a Multimeter?
A multimeter is a instrument that measures electrical properties like resistance, voltage, and present. It’s used to check electrical parts reminiscent of diodes and capacitors.
A multimeter has a dial surrounded by a number of symbols that determine electrical values. There are a number of ports for plugging in electrical leads or jacks. To make use of a multimeter, you have to first choose the proper image on the dial and plug the leads into the proper ports.
In 1920, British Put up Workplace engineer Donald Macadie invented the multimeter. Macadie reportedly grew to become annoyed with having to hold round a number of meters and instruments. So, he constructed a single instrument that mixed a number of meter features.
| Image | Which means |
| V~ (Capital V with wavy line above or the facet) | AC voltage |
| V with two straight strains above it, one dotted and one stable | DC voltage |
| mV | Millivolts (1/1,000th of a volt) |
| ⏦ | AC present |
| ⎓ | DC present |
| mA | Milliamp (1/1,000th of an amp) |
| µA | Microamp (1/1,000,000th of an amp) |
| Oh | Ohms |
| kΩ | Kilohms (1,000 ohms) |
| MΩ | Megaohms (1,000,000 ohms) |
Voltage Symbols
Voltage is the strain that enables electrons to stream from a supply and is provided in each DC (direct present) and AC (alternating present) types. A multimeter can measure each DC and AC voltages.
Present Symbols
Present is both AC or DC and a multimeter is supplied to measure each.
Each AC and DC currents are measured in amps, which refers back to the quantity of electrons flowing by way of the circuit. An amp is the distinction between voltage and resistance, so you too can discover the quantity of amps in a circuit by first discovering the voltage and the resistance of the circuit, after which dividing the volts by the resistance (ohms).
Resistance Symbols
Multimeters measure resistance by sending an electrical present by way of a circuit. The resistance is then offered in ohms.
As a result of completely different electrical circuits can have vastly completely different resistances, there are a number of phases of measurement on a multimeter.
Continuity Take a look at
A multimeter can take a look at for continuity, which exhibits if {an electrical} sign is efficiently traversing the circuit. That is helpful for a lot of conditions, reminiscent of checking if a fuse is blown or {an electrical} part is failing.
To seek out the continuity take a look at operate, search for an emblem that resembles a Wi-Fi image on its facet. When performing a continuity take a look at, the consequence will both be open, which signifies a damaged circuit, or closed, which signifies an intact circuit.
If the multimeter can full the circuit, a 0.000 will seem on the display screen, typically joined by a steady beep.
Diode and Capacitance Take a look at
Multimeters may also take a look at electrical parts like diodes and capacitors and a few may even measure the temperature. To seek out these take a look at features, search for the next symbols:
Diode Take a look at
The diode take a look at is represented by an emblem resembling a right-facing arrow pointing at a cross, each located on a horizontal line. Diodes are electrical parts chargeable for changing AC into DC. Operating a diode take a look at will point out whether or not or not the diodes are working.
Capacitance Take a look at
Capacitors are electrical parts that retailer a cost. Testing capacitors can measure the saved cost. To carry out a capacitance take a look at, search for an emblem that options a vertical line to the left of what seems like a right-facing parenthesis, with a horizontal line crossing by way of each.
Temperature
Some multimeters may even measure the temperature, which is helpful for something from measuring the temperature of the ambient air to measuring the temperature of a transformer or electrical wire. A thermometer image will point out the temperature setting.
Sometimes, a multimeter that may measure temperature will come outfitted with a thermocouple with two leads that plug into jacks on the multimeter. On the opposite finish of the thermocouple is a wire connected to a temperature probe.
Multimeter Jacks
| Jack | Result in Use | Which means |
| COM | Black | Widespread |
| A or 10A | Crimson | Excessive present as much as 10 amps |
| mAVΩ | Crimson | To measure voltage, resistance, temperature, and typically milliamps and microamps. |
| mAµA | Crimson | To measure milliamps and microamps if the instrument solely has 4 jacks, not three. |
| VΩ | Crimson | To measure voltage and resistance if the instrument solely has a mAµA port. |
To make use of a multimeter, insert the pink and black leads into the suitable jack. Most multimeters have three jacks, although some could have 4.
Listed here are the standard jacks discovered on a normal multimeter instrument:
COM
COM stands for frequent and is all the time reserved for the black lead.
A
Place the pink lead within the A jack to measure excessive present as much as 10 amps. This port might also be labeled 10A.
mAVΩ
The mAVΩ jack is used for the pink lead when measuring voltage, resistance, and temperature. If the multimeter is restricted to 3 jacks, this jack can be utilized for measuring delicate currents like milliamps and microamps.
mAµA
If the multimeter has a fourth jack labeled mAµAuse this as a substitute for measuring microamps and milliamps.
VΩ
If the mAµA port is current, it is going to probably have a port beside it labeled VΩ. On this case, this jack is utilized for voltage and resistance.
Different Multimeter Buttons
Completely different multimeters have completely different features, however you’ll be able to depend on these different buttons being current on practically each multimeter:
Shift
The SHIFT button unlocks the second operate of lots of the symbols on the dial. On some multimeters, the shift button is named a operate button or Fn.
To learn the a number of second features, search for writing in a secondary shade above or under the first dial features.
Maintain
The HOLD button freezes no matter studying is at present on the display screen. This lets you reference the studying afterward.
Guide vs. Auto Vary Multimeters
Auto-range multimeters mechanically choose the vary of the values being examined. A guide vary multimeter requires the consumer to pick the vary of the worth being examined (200Ω, 20kΩ, 200kΩ, and many others).
Auto-range multimeters are usually thought of to be practically 100-percent correct. Auto-range multimeters are faster and simpler to make use of than guide multimeters.