Single universal measurement device that can be used to measure voltage [V] and current [A] in both AC and DC, as well as resistance [Ω]. Often many other ranges are available like frequency [Hz], duty cycle [%], capacity [F], ... Most are hand held, some more expensive ones come as a bench model.

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50 views

How does a multimeter sense whether it is measuring single or 3 phase voltages?

How does a multimeter sense whether the voltage we are measuring is single phase or three phase? It might be simple but I have no idea so please help me.
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45 views

Determining internal resistance [on hold]

How do I show that the method used in determining the internal resistance of a milliammeter is just an approximation? We used a 1mA movement.
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0answers
63 views

Multimeter problem with continuity [on hold]

When I turn my multimeter to continuity, it makes a continuous beeping sound that just won't go away. I have replaced the 300mA/250v fuse already. What to do?
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2answers
52 views

Arduino clamp ammeter

I am using an Arduino Uno as a watch dog for a project I a doing; its job is to monitor what is happening in the system and shut down the system if it is not operating within spec. One of the ...
2
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2answers
124 views

Measuring current with multimeter (broken?)

I just got my first multimeter from Home Depot and it was $60. It's the Extech EX330 and it works fine except for when I measure current. I am doing it correctly and the fuse has not been blown. When ...
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1answer
34 views

Why is there a trade-off between AC current measurement and AC voltage measurement?

I am looking at buying a decent digital multimeter (not looking for recommendations), and in the products I have looked at, there is a trade-off between being able to measure \$\mu\$A and mV. eg. ...
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3answers
84 views

Determine break in long circuit

I have a circuit of switches like this. The switches are a long way from the supply and a long way from each other. ...
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7answers
2k views

How should I use a multimeter to determine which AA batteries to keep and which to toss?

I have a bag of about 50 non-rechargeable AA batteries (1.5 V) that I have collected over the years. I bought a multimeter recently and would like to know the best way to test these batteries to ...
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3answers
98 views

Current flow through a battery

So this might be a stupid question and I really should know the answer to it but I am having difficulties with a circuit I have made to drain a battery. The basic idea of this circuit is that I have ...
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2answers
87 views

Difference between DMM and oscilloscope measurements

I have a 220 - 14 V transformer, but when I hook it up to oscilloscope or DMM they show different values. DMM shows 11.8V and oscilloscope shows 17.2. Ok, this is cheap Chinese transformer, so it can ...
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3answers
202 views

Measuring Voltage across a resistor

I am taking my first steps into learning about electronics as a hobbyist and I am struggling to understand something about resistance. I have read about Ohm's law and it seems fairly straightforward ...
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1answer
79 views

Terminology of a “multi-meter” [closed]

I've been having this debate for a while about "what is a multi meter", and they keep saying that a multi meter is what electricians use to get voltage (see:Fluke multimeter), but I honestly believe ...
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2answers
259 views

Multimeter experiment with 10A setting — what happened?

I have a little experience with a multimeter, but I had never used the 10A setting. I was messing around with an old stereo tuner that has four fuse-type lamps used to the light the dial. They are ...
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3answers
303 views

Why do DMMs have so low update/refresh rates?

My DMMs ($50-$100 range) refresh the displayed value every ~250mecs. Are there technical reasons (limitations) for this, or is this just a UI thing?
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47 views

Downsides of using 5mm fuses in 6.3mm sockets

For my multimeter I need to replace a fuse. It is 6.3mm in diameter, 25mm long, rated 500mA/250V AC and 1500A interrupt rating. I have a couple of such fuses, but they are 5mm in diameter, and ...
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2answers
115 views

Measuring Current Consumption of USB Devices

I was trying to measure the current draw of a USB-powered device (a Raspberry Pi) to determine the suitability of powering from an external battery pack. So I took a USB cable, split the +5v (red) ...
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3answers
101 views

Accurate -2V reference

I have an old Keithley 175A multimeter that has been suffering from a bit of drift lately. Internally it uses a 6.35V zener and a couple of resistors to create a -2V reference, but the zener is ...
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2answers
139 views

Resistance measurement voltage - multimeters

What voltage/current is applied by modern multimeters to determine resistance?
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2answers
160 views

Multimeter input impedance and its effect on the measurement of charged capacitor's voltage?

while experimenting with capacitors, I charged a 15pF cap through a resistor to the voltage of a 1.5v battery. Then when I disconnected the capacitor and tried to measure its voltage with a 10Mohm ...
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1answer
110 views

Understanding current readings from a multimeter

If you couldn't guess, I'm new to electronics. So, I've just received my 3V air pump, it didn't come with any specs, so I'm trying to figure everything out. I hooked it up to a DC variable power ...
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4answers
70 views

Range in a multimeter

I'm an Electric Engineering student and I have my first lab tomorrow. One of the questions in the prelab asks you to give the scales and the range of each scale in your multimeter. Here's mine I ...
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1answer
56 views

Measuring the output of a phase control triac

I have an air compressor I'm trying to troubleshoot and I'm trying to determine if the problem is with a small circuit board with a triac. The board takes as input an ac wall outlet (US) and outputs ...
2
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1answer
69 views

Multimeter Manual Precision Explained

When I look some multimeter manuals it says stuff like "0,2% +5", and in videos I hear this as "0,2% plus 5 digits"...but what does it mean in practice? What is this +5 saying?
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1answer
92 views

DMM Auto-Polarity / Polarity detection

I have understood how auto-ranging is typically achieved on a digital multimeter, but I'm having trouble finding an example of how (DC) polarity is handled. How does the meter know if a voltage is ...
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1answer
127 views

Correctly measure L7805ACT regulator output

I am trying to measure the output of a L7805ACT voltage regulator (datasheet) with a multimeter, without any additional parts (no caps, etc, just the regulator). I'm using a regulated wall adapter ...
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1answer
40 views

Can I get the type of clamps that are utilized by the Peak DCA55 Semiconductor analyzer for a multimeter?

I love how on my DCA55 it has push button with clamps that I can use to clamp down on the component I'm testing. Is there a place I might find this attachment for my multimeter? Also, what are the ...
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0answers
118 views

Fluke 8508A reporting back before settling

I'm using a Fluke 8508A for an automated test setup with voltage and current measurements. The test setup ensures that all other devices have settled before and the connections to the input connector ...
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2answers
161 views

Measure peak voltage / amp, when signal is very short (relay on/off)?

I was measuring a 'steer' signal for switching on a relay. The oscilloscope, gave me back it peaks at around 2.64V. The width of the signal is 132ms. I then hooked up my multimeter, to measure how ...
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3answers
216 views

Is “True RMS” applicable only to measuring AC voltage?

Higher end multimeters feature "True RMS" rather than "averaging" voltage measurement. Is this applicable only for AC voltage measurement?
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1answer
91 views

Power consumption of my device

I am trying to measure the power consumption of IFC6410 . The below mentioned schematic describes what I have tried. . (A) works, (B) does not show me any current reading and the board does not boot ...
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3answers
105 views

Getting AC voltage from DC battery

When measuring the AC voltage across a DC battery (CR2032), and I am getting 6v. The DC voltage across it is 3.01 volts. I also tested on a 9 volt battery; again the same thing. I am reading about 20 ...
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1answer
244 views

What are the dangers of a DIY fuse in a multimeter?

For the past few years I have been running my Fluke 79III without a fuse in it's F44.100A 1kV fuse holder. This has meant that I've been unable to use the 40mA circuit. When I blew the old fuse, I ...
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2answers
277 views

How to measure the PWM current with a DMM

I have a Fluke 87V, which is a True-RMS DMM, and I would like to measure the current in my circuit. I have 2 motors being driven by a PWM so I wonder if the DC current or the AC current measurement of ...
2
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1answer
131 views

Different voltage readings when using different ranges on a multimeter

I'm using a digital multimeter to check the voltage on my motorcycle battery - I'm attempting to confirm the proper installation of a new alternator in the charging system. The voltmeter has 3 ranges ...
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2answers
1k views

Why do measurements displayed in multimeter inconsistently vary by factors of 1000 depending on range?

For my science fair project, I am measuring the resistance of a 100 foot piece of 32 gauge Nichrome wire. Using a Innova 3300 digital multimeter, I get the following results for each resistance range ...
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1answer
165 views

In a non auto-ranging digital multimeter, what do the increasing numbers in the Ohm section represent?

For my science fair project I am measuring the resistance of nichrome wires under different conditions. I am using an Innova 3300 digital multimeter to measure the resistance. Other websites have told ...
2
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1answer
87 views

How to measure open-drain vs. hi-z with multimeter

I have an output pin configured to be either open-drain or hi-z. How can I use my multimeter to tell which mode it is in?
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2answers
3k views

Why don't typical digital multimeters measure inductance?

Even with predominantly digital circuits, I am using inductors much more often than I used to, generally because of all the buck or boost converters (a recent board I was involved in has 12 different ...
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1answer
214 views

How to check if a comparator is broken?

I have just started experimenting with electronics and am concerned that I may have destroyed my LM339 comparator circuit. As a basic test, I had a 3.0 volt power supply hooked up to the Vcc pin and ...
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3answers
116 views

Why does a voltmeter show voltage drop

Consider this circuit. What would I get if I measure over R1? It should be less than 12v, right? But then what volatage is LAMP1 running at? Is it still 12v, or is it the voltage I measured across ...
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2answers
314 views

Why does a voltmeter read lower across a load than across a supply?

From the Wikipedia article about series and parallel circuits: As an example, consider a very simple circuit consisting of four light bulbs and one 6 V battery. If a wire joins the battery to one ...
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2answers
54 views

Current measurement maximum time

On my multimeter I have two current measurement connection. One for the mA and one for the A. On the ampere one there's a time limitation but not on the mA one. Also they mention in the manual a kind ...
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1answer
102 views

Measuring Voltage and Curent Simultaneously with Probe?

I have very little experience with electricity, but I am doing a project in which I need to measure power output of solar cells. I am currently using this: ...
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2answers
80 views

Multimeter resistance measure

I've found this question but they don't talk about damage (Multimeter ranges) If I measure a 20KOhm resistance an I'm for example in the 200Ohm range, can this damage my multimeter ?
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3answers
238 views

Measuring current drawn on a 12V barrel plug

I would like to replace my monitor power supply it's 12V 3A and I doubt it's actually necessary -- old LCDs were pulling that current and this is not CCFL but LED. So I would like to measure the ...
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2answers
169 views

How to measure current with multimeter

I want to measure both voltage and current from an output expansion port, of the BeagleBoard-xM. I managed to measure voltage by putting measuring lead (red) to the expansion port and reference lead ...
5
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2answers
116 views

Accuracy when measuring current (mAmps) and small voltages

I'm looking at a circuit (part of a bigger circuit) that consist of a 10 ohm resistor and a red LED. It's running on 2.05V (checked with 2 different multimeters, ranging from from 2.047V to 2.05V). ...
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1answer
73 views

Tried to measure current with red lead in voltage socket - bad for multimeter?

I just tried to measure the current that my circuit draws when powered by 2xAAA batteries (3 V) using my Fluke 87-V. I connected the leads in series with the battery, but I accidentally left the red ...
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1answer
200 views

Clarify multimeter current reading range?

I'm a bit confused about the range on my multimeter. I have connected the multimeter to a 5V USB wall charger rated at 1.3A. When I'm measuring voltage, everything makes sense. It shows a 1 for 200m ...
5
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3answers
455 views

Why isn't ammeter protected with a fuse

Why is it that the ammeter with low current (200mA) limit are fused and not the 20A one? I recently lost a multimeter because i connected the ammeter in parallel by mistake. Edit: All the ammeters i ...