How to Measure Watts with a Multimeter | Galco

To measure watts with a multimeter, begin by choosing the voltage setting on your multimeter dial. Make sure that the appropriate voltage range is selected. In many cases, it is best to select the highest possible voltage range to prevent a possible overload, unless your meter has Auto-Ranging.
Connect your red multimeter lead into the port marked for voltage for the correct range that you are testing. You can keep the black lead in the common position.

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#multimeter #digital #watts #measurement

[skyarmy]

You can use this method to measure watts, but there is a small error. Although it works if you don't have a wattmeter, it will never be as accurate as a wattmeter. When using this method on AC circuits, it's important to consider the Power Factor (PF), denoted as "cos(φ)". If the load is purely resistive, then PF=1. In most homes, you will find devices with a PF close to 1. However, you might encounter appliances with a PF<1, such as an AC fan motor that consumes something like 18 watts. If the PF is 0.707, then only 9 watts are used for useful work. However, this is not a significant issue due to its low consumption.

[gluino]

This video is correct for DC circuits. If it were AC, you'd need to consider whether the load is resistive, if it isn't the watts would be likely somewhat lower than the simply multiplied VA.

[damiencook]

So how does this measure consumption? It shows me the voltage of the circuit, not the load as the title states?

[ColumbiaWaterGardens]

Thanks for this fast, short, and simple explanation.

[dragan]

It's easier to use a line splitter. Plug any device in and clamp an ammeter around 1 of the conducters. If you have a heater? It's rated 2400watts? 240 volts on power point? Amps would read 10 Amps maximum on the clamp style ammeter. 240 volts times 10 Amps = 2400 watts. BTW! Bear in mind the power outlets don't always put out say: 240 volts AC! I've seen 230 volts. This is the way I was taught by an electrician. I have measured with a wattmeter and almost spot on every time. Don't worry about power factor as certain appliances make the power factor change to the point that you're using more Amps than when an appliance is turned on! This is due to wasted heat on an air-conditioning system for example. I have used a spray bottle on a small air-conditioning window mount unit and I have seen the power factor change to almost perfect! This is my way of testing and always almost spot on with a power meter. Like a kill a watt meter!

[RobertLongM]

I'm confused
Volts x Amps
If I have a circuit board (amplifier i/o to a speaker)
9 volt battery powered

So? The demo was confusing.
If I put the leads up to my +/- where the speaker is connected to...what amp I multiplying it by?

[TearfulNight]

its only for DC calculation guys ..not AC .. BEWARE

[tule-hzmj]

Wrong, Volts X Amps is VA which is Apparent Power.

[donaldteed]

Useless. The video shows a multimeter, which only measures voltage, not amps. Then it goes off and does some math. You cannot measure watts with a multimeter, so don't imply it with the title.

[arpitjain]

misleading incorrect video, should have mentioned only for DC

[fourfortyroadrunner]

Very poor video, very poor explanation. No context. Measurement practice borders on unsafe if this were a power line voltage circuit.