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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6
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6answers
10k views

Wrong multimeter readings measuring 12V lead acid battery

I just got my first multimeter and when I measured a 12V 1.2ah lead-acid battery I get AC 28.8V and DC 13.4V. Is this normal? In addition I tested an AA 1.5V battery and I got 2.9V (AC setting 200) ...
2
votes
1answer
599 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 ...
6
votes
2answers
98 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 ...
0
votes
2answers
370 views

When measuring a resistor with a multimeter does polarity matter?

When measuring the resistance of a resistor using a multimeter does it matter if I turned the resistor around and have the probes at opposite leads? Should I get the same results?
21
votes
5answers
23k views

What not to do with a Multimeter

So I just bought and installed a new fuse for an analog multimeter I scored for free and now it works like a charm. The new fuse is the same rating as the blown one I found inside, which is 0.5A 250V....
8
votes
5answers
1k 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 ...
10
votes
2answers
2k views

How to calibrate multimeters?

Without buying an expensive calibration tool, how can I accurately calibrate my multimeters?
8
votes
1answer
2k views

Why can't a multimeter measure its own current and voltage?

Well I finally obtained another multimeter, so now I have a Mastech MS8226T and a Ben Electronic M92A. I decided to measure at which voltages would the low battery warning appear and how much current ...
11
votes
10answers
17k views

Is it worth really buying a Fluke for hobbyist use?

Well, the question is the title: Is it worth really buying a Fluke for hobbyist use? I have a cheap meter at the moment. Is it worth spending a 3 figure sum on a nice, shiny, new Fluke? I honestly ...
8
votes
5answers
26k views

how to measure the internal resistance of a voltmeter?

How to find out what is the internal resistance of a voltmeter? I imagine the higher the better - it'll have less influence on the measured circuit. What is the approximate internal resistance of ...
5
votes
2answers
157 views

What features give reason for such a wide range of prices for digital multi-meters?

Ever since high school, I've been using the same multi-meter. It works well for low voltage purposes, but I'm scared to use it for anything else (high voltage, unless it's a little zap from an ...
7
votes
1answer
13k views

How to determine the units when reading a multimeter?

Say for instance I am trying to measure the current. The units around the edge of the multimeter is 2000u, 200m, 20m, 10A, etc. Does this mean that the reading displayed on the multimeter is in that ...
3
votes
3answers
3k views

Measure voltage difference between ground and DC floating power supply lines

110/220V AC to 12V DC switching mode power supply (metal enclosed, input is 220V with separate L,N and ground.) Measured voltage difference with a multimeter between V- and V+ 12V DC as expected ...
12
votes
2answers
6k views

Can I burn components / short circuit by using a multimeter

It's probably not new to you, but sometimes we want to analyze a powered circuit with a multimeter. I love to do that, but I'm a little worried that I might burn some components or the whole circuit. ...
11
votes
2answers
3k views

Why one of my multimeter shows a small voltage when only one probe is connected to AC and the other dont?

I've recently acquired a Minipa ET-997 multimeter. I noticed that when I connected one probe to 127V phase and let the other disconnected, it will show around 12V. But I have an older and cheaper ...
11
votes
4answers
3k 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?
8
votes
1answer
5k views

How does autoranging work in a multimeter? What is the circuit?

I was curious how this is done. It seems you would have to vary the voltage and current to measure resistance from 1ohm to 10Mohm.
7
votes
4answers
1k views

Why aren't high-current ammeters protected with a fuse

Why is it that the low-current range on an ammeter (200mA) is fused and not the 20A range? I recently lost a multimeter because I connected the ammeter in parallel with a power source by mistake. ...
6
votes
3answers
1k 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?
6
votes
3answers
385 views

4.75 digit count meters explained

What does it mean for a digital instrument when its readout is 4.75 digits "long'. And what is it like in comparison to, say a 4.5 digit meter?
4
votes
3answers
3k views

Multimeter ranges

I am a software developer trying to understand how computers work at a lower level. I have purchased a digital MultiMeter. I realise that MultiMeters enable you to measure voltages, ohms, amps etc. ...
4
votes
1answer
680 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 ...
3
votes
2answers
2k views

How do I fix my multimeter, which doesn't seem able to measure resistance?

I've got a Caltek CM1200 multimeter, which I bought ages ago. http://www.caltek.com.hk/cm1200.htm It can measure voltage perfectly. I'm pretty sure the battery works, as it displays 0 when you go ...
3
votes
4answers
3k views

different current readings with a multimeter between the 200 mA and the 10 A slots

I have a cheap multimeter, which gives me different readings between the two inputs. I would like to set 100 mA using a potentiometer in a circuit, which runs from two AA batteries. If I measure the ...
2
votes
1answer
2k 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 ...
2
votes
1answer
4k views

How do I choose the right replacement fuse for my multimeter?

I have a BK Precision 2709B Multimeter. I managed to blow the uA fuse (500mA/500V fast blow ceramic) on it. Is it an ok to replace this fuse with a 500mA/1kV fast blow ceramic fuse? What impact would ...
2
votes
3answers
3k views

How usable can results of measuring MOSFET resistance with a multimeter be?

When the resistance of a MOSFET at a certain gate voltage and current is needed, the correct value is ordinarily obtained by reading the datasheet for specified values. Since a MOSFET is supposed to ...
2
votes
4answers
3k views

How can I test my multimeter's battery without a low battery indicator?

I a few months ago needed a multimeter, and I didn't have one. Not wanting to wait for one to arrive, and only needing it once, I went out to the hardware store and bought a cheap digital multimeter. ...
2
votes
2answers
19k 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 ...
1
vote
1answer
789 views

What's the low voltage displayed by a voltmeter when only one of its probes is connected?

Recently I was toying with a digital multimeter and observed the following. The multimeter was set to measuring AC voltage with the upper limit of 750 volts. It has two probes which I will call "red" ...
1
vote
4answers
598 views

Failed multimeter

I have a cheap handheld multimeter that has stopped working. It basically behaves as if the leads weren't connected: the Vdc readout stays at zero, and the ...
1
vote
3answers
299 views

Why can't I measure resistance when there is current on the potentiometer?

Probably a very basic question but I have no idea why this happens. I have a 1K potentiometer. When I measure the resistance over its legs when it is not connected to anything, the results are as ...
1
vote
0answers
513 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 ...
0
votes
1answer
124 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 ...
0
votes
1answer
73 views

power supply multimeter voltage test differ from the label

I have a router's power supply. 12 Volts is written on the label. When I use a multimeter the voltage is 16.80V. Should I use it to power a small LED strip that requires 12V?
0
votes
4answers
111 views

Using a multimeter

Online I've seen more simpler multimeters that you choose what your measuring. How do I use a multimeter like this for measurement