In the s, when having electronic devices became a reality for a lot of people and radios became the cool thing to have, multimeters were born as a result of Donald Macadie. Those pesky vacuum tube electronics were always malfunctioning and required special attention to seek and alleviate its electronic malfunctioning components. From there on, the multimeter sustained small and incremental improvements until they became the devices we have today.
His invention truly changed the lives of every electrician, handyman, engineer, mechanic, and hobbyist who has ever worked with electronics. Most, if not all multimeters have three distinct parts: A display, selection knob or switch, and at least two ports where wired probes are connected to them. The display on most multimeters on the market today typically readout in four digits and are capable of measuring in positive or negative units. The fancy multimeters have a handy dandy backlit display, making for the readout display usable in low light situations.
The selection knob is used to choose what the multimeter will measure. Each of the selections available is to measure in a specified range.
For example, setting the selector knob to the 20V setting will give you a readout between 2 and If you receive just a 1, you might be testing a current that is too powerful for the specified range, thus requiring you to select a higher range to find the information you need. Although the color-coded wires are for organization purposes and the meter will work with them in either order, it can be important to use the colors in the proper port each time to avoid confusion.
The black wire is almost universally accepted at least within the U. A as the ground wire and is marked -. Depending on the model of your DMM there could be several ports on the front of your meter which you will need to plug your probes into the appropriate configuration depending on the parameter you are needing to measure. One common example of this is measuring current. This is due to HOW your meter goes about doing its job. When measuring a Voltage or Resistance, your meter typically needs to be in parallel with the component you are measuring If interest, read here for more on parallel components.
When measuring electrical current, your meter typically needs to be configured within the circuit in series with the portion of the circuit you are measuring If interest, read here for more on in-series components By failing to measure current by placing the meter in series with the circuit, you risk blowing the internal fuse of the meter.
If you lose or damage one of the wired probes you do not need to purchase a new multimeter. There is also a wide range of different probes that you can use for different applications.
The ammeter function measures the number of electrons passing a given point over a specified period of time, which is measured as a current. The units this measurement is displayed in will be given as amperes. This allows the user to identify electronics that are overdrawing current and likely to cause circuit breakers to trip. The ohmmeter function is used to measure electrical resistance. This resistance is referring to the opposition in electrical current and is measured in ohms.
You can identify a short-circuit by measuring 0 ohms and sometimes a unit near 0 will also indicate a short-circuit. When a circuit is open, the meter should read infinite resistance and no current flow. You can measure voltage in either direct current DC or alternating current AC.
In regards to a typical household outlet found in the USA, the outlet is most likely using AC, however, this can vary in some countries prefer using DC. When testing voltages and currents in your house, it is important to exercise extreme caution. You can really ruin your day, or your life, depending on how high the current it is. If you are comfortable doing the work on your own, please use all safe electrical work practices as well as personal protective equipment PPE.
Press the probes against the resistor legs and apply light pressure, ensuring good consistent contact on each side of the resistor. Your meter should show either 0. If it reads 0. If you see a reasonable number between 0. Resistors are also typically color-coded so you can use the resistance color code to determine its resistance by using this chart: Resistor Color Code As a final tidbit regarding resistor measurements, keep in mind that measuring a resistor installed on a circuit board may greatly impact the measurement you receive due to other components drawing on the resistor itself.
You can learn more about measuring resistance with a multimeter here. Pull out the VCC wire leading to the resistor and add a wire where that wire was connected. Then use your probes on the power pin from the power supply to the resistor. If you suspect the current to be higher than mA, you may want to use the 10A port on your meter, otherwise risking blowing a fuse. Note that you may want to use alligator clips as you should observe the measurements over a period of several seconds or even several minutes.
Continuity simply means there is resistance between two specified points. If the points in question are connected, the multimeter should emit a tone, and if they are not, leaving the circuit open, there should be no tone emitted.
To set your multimeter to check continuity, turn the selection knob until it indicates the symbol that looks like the WIFI strength symbol turned on its side. Some multimeters may have a different symbol so you may just need to consult with its user manual. You should receive an audible notification through some kind of tone. Turn off the electrical system first and then use the probes on the two separate ground pins.
You should hear the tone. A tone should be audible, indicating power is capable of flowing from the VCC pin to the controller. Pro tip: some systems can contain residual power due to the extra capacitance which may set off your multimeters tone for a super quick moment. Ignore that and focus on the tones they are strong and lengthy.
You can use this as an integrity check before fully powering on a new system. Need more help? Just kidding, your multimeters come equipped with a safety fuse that will blow, protecting your multimeters internals from catastrophic failure if you accidentally use it on the incorrect settings.
Accidents happen and this stuff is difficult! Grab a screwdriver that will fit and remove the backplate sometimes on the front or the side from your multimeter.
Next, yank out the battery and set everything loose aside. There will likely be a few more screws to take out and then you can lift up the face of the multimeter off of its body.
Some of these have hooks, tabs, or something else holding them together. Be careful not to break them and try to remember how everything came apart so that you can put that bad boy back together again. Once the board is visible you should see a blown up tube fuse. The fuses are usually situated right next to the ports that your banana connectors slide into. Simply lift it out of its little holder and discard the blown fuse. Make sure you replace the fuse with the exact same fuse that is rated for the same amount of power.
The metal cap on the end of the fuse should indicate what the fuse is rated for. First and foremost, a solid clicking feel on the selector knob is a pretty good indication of quality. Many multimeters come with similar functions in a similar form factor but the way they are built can range drastically. A fancy feature that people who use their multimeters regularly might want to have available to them is the auto-ranging feature. This means the multimeter is capable of automatically changing their internal range to find the best range that provides the highest accuracy.
Another thing to look out for is probe quality. Just like those cheap Walmart headphones that always end up with one earbud working and one not, probes internal wiring can come undone and stop working.
The last thing you want is a faulty probe when trying to figure out what electronic components are faulty! Most decent multimeters nowadays come with an auto shut off function.
It would be a major drag to have a dead multimeter and no spare batteries lying around when you really need your meter in a pinch. Hello, my name is Chris and I was born and raised in Western Pennsylvania.
I have been with my current employer for more than 5 years developing digital control systems for nuclear power plants. My goal is to take all my technical knowledge and first-hand experience and translate it into high-quality content to support all of your home guide needs. Whether it be step-by-step guides, technical consultation, or product reviews, my aim is to make all your home projects a great success!
A digital multimeter DMM is an essential testing tool for any electrical project. Similar to the label, the value label is always placed above the track. The width of a meter can be customized appropriately for its context. The default width is size px on desktop and px on mobile.
Meters come in 2 sizes: large and small. By default, meters are large. The small size is used when there are multiple meters shown at the same time in a more confined space e. The value shows a quantity or an achievement, from 0 to 1, such as tutorials completed, storage space, etc. Unlike the progress bar , this value is determined by user actions, rather than system actions. From the design point of view, each component has a number of options. These options and their names are platform agnostic, and each implementation should adapt these to fit into their framework.
When the label is too long for the available horizontal space, it wraps to form another line. The value is always shown in full and never wraps or truncates. A progress bar fills automatically as the system loads determinately or indeterminately. A user's actions do not affect the progress bar; it just indicates how long they must wait for the process to finish. A meter indicates how much the user has completed or how far they are in a continuum. Use the built-in style for showing a label associated with the meter.
This style always has a left aligned label and an optional right aligned value above the track. The label should be in sentence case. When a stack of meters appears in a table, the label can also be in the form of a table column header.
Meter variants can be used to represent semantic values by switching variants as the value changes, from positive, to notice, and then to negative. For RTL right-to-left languages, the layout of the meter is mirrored.
The label is right-aligned, the value is left-aligned, and the fill progresses from right to left. Beware that the placement of the percent sign differs depending on the locale. Includes all interactive states that are applicable hover, down, focus, keyboard focus, disabled. Works properly across all four color themes lightest, light, dark, darkest.
Color is not used as the only visual means of conveying information WCAG 2. Text has a contrast ratio of at least 4. Visual information required to identify components and states except inactive components has a contrast ratio of at least WCAG 2. UI language and information design considerations have been incorporated into component design.
Includes relevant options variant, style, size, orientation, optional iconography, decorations, selection, error state, etc. Includes guidelines for keyboard focus, layout wrapping, truncation, overflow , animation, interactions, etc. Includes a list of dos and don'ts that highlight best practices and common mistakes. Includes content standards or usage guidelines for how to write or format in-product content for the component.
Works properly across various locales and includes guidelines for bi-directionality RTL. Follows WCAG 2. All design attributes color, typography, layout, animation, etc. Includes a downloadable XD file that shows multiple options, states, color themes, and platform scales. Includes a downloadable XD file, generated by code using design tokens defined in Spectrum DNA, and shows multiple options, states, color themes, and platform scales. No results found. Spectrum Principles What's new.
Application frame Responsive grid. Divider Popover Tray. Badge Meter Progress bar Progress circle Status light. Heading Body Detail Code. Cards Headers Table. Contact us.
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