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.

learn more… | top users | synonyms (1)

-4
votes
1answer
69 views

How to Test IC Using a Multimeter [on hold]

A few Days Back We Had A Competition in Which They Gave us Various ICs Placed on a 8085 Trainer Kit the Number on ICs were Hidden and We Were Asked to find Which ICs were They Just By Using a ...
0
votes
1answer
33 views

Battery voltage increasing while measuring (NiMH)

I was going through conditioning for a NiMH battery pack (12 x 1.2V, 1500mAh cell) and decided to check the cell voltages. I noticed that the measured voltage, with a multimeter, increased over time. ...
-2
votes
2answers
64 views

How Cheap AC Clamp Meter Reading on DC Current?

Harbor Freight's cheap CEN-TECH clamp meter does register on DC wires. For example, 12V powering an inverter at about 10 amps current DC from the battery to the inverter reads +1.68 amp then +1.52 ...
0
votes
0answers
41 views

Why does multimeter show a voltage of 10 volts in AC mode when I try to measure the output voltage of 5 volt supply? [duplicate]

I was carrying out a small experiment on the working of regulated power supply that consisted of a Transformer, a bridge rectifier followed by filters. I applied 230 volts from the AC mains. Using my ...
0
votes
3answers
108 views

Why won't this bulb light when I put the multimeter in series?

It lights here with no multimeter, this is fine But if I replace one of those wires with the multimeter, connecting the multimeter in series, then the bulb doesn't light. I am wanting to measure ...
1
vote
1answer
55 views

Common voltage when use a battery powered DMM to measure a voltage

I'm a little confused by the common-mode voltage in this situation: Assume you use a DMM to measure a signal generator's output voltage, the signal generator is grounded, apprently the DMM is not. If ...
0
votes
1answer
64 views

Voltage sensing using Arduino with and without common reference

I wish to make a voltage sensing circuit (range -15V to +15V) using an Arduino's ADC. The problem is that since this circuit will be part of a much larger circuit in which the Arduino is performing ...
0
votes
2answers
109 views

Measuring uA current with DMM?

I'm wondering if anyone knows the accuracy of measuring uA current with a cheep (~25$) DMM? I need to measure some low power circuits (10-500uA) and I'm deciding whether I should get an analog uA ...
0
votes
2answers
57 views

What am I doing wrong here? LED and Multimeter [Noob]

As a disclaimer, I am new to this and this is my first multimeter but I have tried researching this problem before asking here, I seem to be doing what the other people do in videos but getting no ...
2
votes
1answer
72 views

How to test a crystal with multimeter

I have a PCB in which I need to change the crystal. I don't have scope right now with me. So is there any way I can check if the crystal is working or not after soldering it in PCB. I am not good in ...
3
votes
3answers
77 views

Can probing an EEPROM with a multimeter corrupt the data?

Say there's an EEPROM on a board and you happen to try probing the pin one by one with a multimeter, is there a good chance that the sequence of probing the pins must have overwritten (thus corrupt) ...
3
votes
6answers
862 views

Why am I getting very different measurement results on a breadboard?

I have an AC to DC multiple output adapter. It has the following output: I set the voltage to 5V. When I measure the supplied current, I get 3.26A. Then I connect an output to it: When I ...
6
votes
3answers
335 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?
1
vote
3answers
140 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
votes
1answer
75 views

How to measure voltage of a track lighting fixture?

My house has track lighting that takes MR16 halogen bulbs. I would like to measure the voltage being put out by the fixture using a multimeter. I removed one bulb, set my multimeter to V-DC and ...
0
votes
1answer
111 views

A DC micro-voltmeter

Basically I will be calibrating circuits to a high degree of precision. Keeping it minimalistic, I figure all I needed for that are resistor networks, voltmeters and a few high precision voltage ...
0
votes
2answers
89 views

Choose between two multimeters [closed]

I want to buy one low budget multimeter for regular use. I don't need any high end functions only the basic ones (measure current, voltage and resistance). I have found these two multimeters (1), (2) ...
2
votes
3answers
169 views

Possibly Incorrect Current Reading

I'm not entirely sure if I have done the following equation correct or not, but based on the calculations, my multimeter result seems to be incorrect. I have a very simple circuit, containing a 9V ...
-2
votes
2answers
195 views

How does the internal resistance of oscilloscope compare to that of the DMM? [closed]

Both are the instruments that measure voltage, so what are the difference between multimeter and oscilloscope in terms of their internal resistance ?
10
votes
4answers
872 views

Why do multimeters have an aluminium foil at the back?

I was wondering what is the purpose of aluminium foil at the back of some multimeters? I did a continuity test and found that it is connected to the ground (COM) terminal. My initial guess was that ...
-3
votes
1answer
112 views

School Project : To determine Eq. resistance of a cube whose each edge has a resistor, say R [closed]

Background I am a high school student, we are supposed to submit a Physics Project, individually. Since I have never done any Electrical Project/Experiment before, I came up with the idea of making a ...
3
votes
2answers
707 views

Phantom Voltage When Near Outlet?

I am pretty new to electronics, and have mainly worked with DC circuits. I'm majoring in Computer Science, but I also find electrical engineering interesting, so I am learning as much as I can. Well, ...
2
votes
1answer
108 views

Review of: voltmeter, ampmeter, ohmmeter circuits for Arduino [closed]

I'd like to build a multimeter with an Arduino Due. Could you review the following circuits and tell me what I should improve? Voltmeter Requirements: Ranges: -30V -> 30V, split into a) ...
1
vote
1answer
57 views

Would a charged capacitor react differently to a continuity test than a discharged?

I'm testing my non-reacting circuit with a multimeter, but I don't know if I have to discharge my capacitors first or not. I use two capacitors: 0,1 uF and 560 pF.
0
votes
2answers
143 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?
0
votes
5answers
146 views

When measuring a resistance using a multimeter it is a few percent out. Why?

For example, if you were to put 5V across a \$150\Omega\$ resistor and measure its resistance with a multimeter, the reading would always be a few percent off the true value. What reasons might there ...
0
votes
0answers
62 views

Multimeter continuity test on MOSFET

I am driving AC/DC motors using a driver board. The board has IR2104 as the MOSFET driver and IRF630 as the MOSFET and three half bridges(one for each phase of a 3 phase motor, Supply = 60VDC). ...
0
votes
0answers
57 views

Measuring voltage drop with an op-amp

For a uni project I'm required to design a multimeter. One aspect of the multimeter is to measure DC voltage in the range (0-10V). So far I have just setup a simple voltage follower op-amp ...
3
votes
1answer
100 views

Is it possible to measure the voltage produced in heart

I learnt from my high school biology that human heart will produce about 1mV from the sinoatrial node.(voltage will vary like the graph in ECG test).Is it possible to measure the voltage with any ...
0
votes
1answer
105 views

Microphone voltage output - is it AC?

Can anyone tell me if the output voltage of a microphone (like the type on a webcam) is an AC voltage? And whatever it is, can it be measured on a standard voltmeter? Thank you.
1
vote
1answer
85 views

how to calculate input, output, and feedback resisters of an OP AMP given voltage In/Out

I'm trying to solve for \$R_{x}\$, \$R_{y}\$, and \$R_{z}\$, given a know \$R_{1}\$, \$R_{2}\$, \$V_{in}\$, \$V_{out}\$, \$I_{in}\$, \$I_{sc}\$, \$V_{CC}\$, and \V_{EE}\$, \$V_{CC}\$ , \$V_{EE}\$, ...
1
vote
2answers
704 views

Why does my multimeter always show a value of 1 for resistance?

I have a brand new multimeter, but any time I set it to resistance mode (any setting) according to the user manual, it shows 1 in the leftmost digit, and the ...
12
votes
6answers
4k views

Why are these readings violating ohm's law? (Are they?)

I'm brushing up on my high school electronics knowledge and I decided to experiment with a small acquarium pump I had lying around. I took some measurements with a multimeter and the results confuse ...
1
vote
0answers
59 views

Do “True RMS” meters really do RMS if the input is a high frequency signal?

I'd like to measure the average of a signal which is mostly zero (less than a few nanovolts as best as I can tell) but may have occasional nonzero "blips" of maybe 20-100 nanoseconds (maybe 1V tall). ...
0
votes
5answers
350 views

Continuity Test on Resistor

I have a newbie question. I'm learning about electrical engineering and I bought my first multi-meter. It has a feature called "Continuity Test". I believe this test is to make sure conductors such as ...
0
votes
2answers
84 views

can I place 250ma fuse instead of 200ma fuse in multimeter, affacts meter calibration? [closed]

Well I know that it fuse will pass more 50ma in my multimeter but I want to know that will it make some change in my calibration of multimeter? can more 50ma current can damage my meter?
1
vote
1answer
88 views

Why is my milliamp and microamp current reading so different?

When I check the current in my circuit using milliamp I get around 2.54 milliAmp. When I use the microamp setting, I get 1844 microAmps which translates to around 1.84 milliAmp. Why is this ...
1
vote
2answers
95 views

Why does my current in parallel circuit not add up when I check using a multimeter?

I have a simple circuit 9v connected to 3K resistor coneected to a wire. On this wire, I have two LED's connected in parallel, both leading straight to ground. When I check insert my multimeter ...
1
vote
1answer
30 views

DMM Spec Sheet Trouble

I am wondering what the "Transfer" column indicates in this spec sheet for the Keithley Model 2002 DMM, and how it should be incorporated into any uncertainty calculations. Thank You!
2
votes
2answers
259 views

Under which possible conditions is measuring with an multimeter a danger to life ?

My knowledge of electrics is very limited, I am planning to buy a Multimeter, but I am confused when it comes to safety. I do not really know what is a danger to life when measuring a circuit with a ...
0
votes
3answers
102 views

Is there such a thing as a multimeter with needle prongs as small as an exacto knife tip? [closed]

im working with repairing cell phones and I need to test connectivity, but the multi-meters that i have too big of a tip. are there micro tip multi-meters for precision use on tiny chips as small as ...
0
votes
1answer
77 views

Testing Capacitors - Differing Results Each Time One Is Tested?

I have a bust LCD TV - I've already ordered a replacement but am interested in using the broken TV to learn a little more about how these are put together and if I'm lucky fix it to have as a spare. ...
2
votes
2answers
969 views

Why would you use a non-contact voltage detector if you have a multimeter?

I was reading this Fluke multimeter safety manual and I came across this sentence: ...
0
votes
0answers
56 views

Impedance measurement for open circuit not staying constant

I'm trying to measure all the impedances (Power and critical I/O Pins at a test point) of the board using multimeter. When i measure ground and ground its showing close to zero, which is fine. But for ...
1
vote
1answer
117 views

checking for 'dirty' power on a power supply using only a multimeter?

this is a follow up from http://superuser.com/a/958165/43268 It was suggested that i check a 19VDC power supply for "dirty" voltage. If i had a oscilloscope i could probably follow the excellently ...
10
votes
3answers
1k views

“Beep” when testing VCC and GND with the multimeter

Sometimes I use my multimeter solely for testing if there is a contact between two points. However, sometimes, when I measure between VCC and GND on some of my PCBs, I hear a short "Beep" and then it ...
0
votes
3answers
62 views

How to measure temporary drop in voltage with meter

What's the easiest way to measure the period of time between the "peaks" when a 5V DC signal goes from high to low to high? I'm trying to debug a power-loss problem, and one of the solutions I'm ...
1
vote
1answer
74 views

Multimeter giving wrong current readings

I just got my first multimeter (TekPower TP8268) and I've been try to test it out, but I have been getting some strange readings with the current measurement. I have an AC adaptor to DC 12v and 5A. ...
0
votes
2answers
212 views

Measuring low voltage AC current with a multimeter

I know that with DC you can measure current by putting your meter in series with the positive supply. I have a project running off a low voltage AC supply. Can I do the same?
6
votes
4answers
476 views

Multimeter measurement

Looking for help with reading my multimeter. I would think by moving from 20 to 200, the decimal place would just shift one place. Why when I switch do I get a reading of 20ma vs 10ma?