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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0
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3answers
89 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 ...
0
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2answers
74 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 ...
3
votes
3answers
187 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 ...
-8
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1answer
74 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 ...
2
votes
2answers
233 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 ...
5
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3answers
294 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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1answer
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 ...
1
vote
2answers
100 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) ...
2
votes
3answers
97 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 ...
4
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2answers
137 views

Resistance measurement voltage - multimeters

What voltage/current is applied by modern multimeters to determine resistance?
1
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2answers
123 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 ...
2
votes
1answer
103 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 ...
1
vote
4answers
65 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 ...
0
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1answer
50 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
votes
1answer
66 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?
1
vote
1answer
86 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 ...
0
votes
1answer
117 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 ...
0
votes
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 ...
1
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0answers
113 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 ...
3
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2answers
154 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 ...
1
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3answers
168 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?
0
votes
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 ...
1
vote
3answers
100 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 ...
1
vote
1answer
225 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 ...
4
votes
2answers
246 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
votes
1answer
117 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 ...
0
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2answers
749 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 ...
2
votes
1answer
146 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
votes
1answer
83 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?
19
votes
2answers
2k 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 ...
1
vote
1answer
182 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 ...
0
votes
3answers
109 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 ...
1
vote
2answers
271 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 ...
3
votes
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 ...
1
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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: ...
0
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2answers
77 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 ?
0
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3answers
225 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 ...
0
votes
2answers
160 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
votes
2answers
113 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). ...
1
vote
1answer
70 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 ...
1
vote
1answer
171 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
votes
3answers
439 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 ...
0
votes
0answers
124 views

Measuring the frequency of a 0-5V signal with DMM and no oscilloscope?

I'm trying to determine whether I can use a DMM to monitor a 0-5V signal of a cam and crank sensor. Both are magnetic. I have a 5V ref. The sensors should vary between 0V and 5V with a short pause ...
5
votes
4answers
392 views

Detect electrical signals from plants

My daughter wants to do a science fair experiment that involves reading the electrical signals in plants, but the cost of a multi voltmeter with data logging is very high. Can anyone suggest a setup ...
4
votes
2answers
596 views

What does it mean that a multimeter is four and a half digit?

The fluke 87-V is advertised as a "four and a half digit" meter. What does that mean, how does half a digit fit into the equation?
4
votes
1answer
147 views

Multimeter reads negative even without leads

I have a cheap multimeter that used to work fine but now it has negative readings -- even when the leads aren't connected. I changed the battery, looked for a blown fuse but no luck. Any idea what's ...
0
votes
1answer
90 views

Using a DMM to measure output isolation/crosstalk

I'm making some PCB's that have some DC to DC converters on them with three 5 Volt converters, one 15 volt converter, and a converter with +/- 12 volts DC. On the PCB the output pins are in a ...
9
votes
2answers
510 views

Why does a multimeter put more voltage to measure a smaller resistance?

I noticed this behaviour on two different multimeters (different models and brands as well). At first I did not put a multimeter in the way to measure how much voltage changed for the different scales ...
2
votes
1answer
245 views

How to interpret diode-mode readings from a multimeter

I'm using this multimeter to examine a heat gun fan. The fan has four contacts placed in a circle (well in a square inside a circle). Two opposite each other are labeled ...
0
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0answers
230 views

Why does a multimeter in resistance mode show initial continuity over a diode?

I originally phrased this question very differently; the original text is retained below in case background information is useful to clarify the context. When I using this digital multimeter to ...