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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2
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1answer
90 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) because I purchased it in 1993 or 1994. ...
-2
votes
1answer
33 views

DMM 1000 Volt switch [on hold]

I am trying to design a digital multi meter and the switch on the incoming voltage line needs to be 1000 V. Since all commercial DMM use custom made switches to handle the high voltages coming in. ...
0
votes
3answers
88 views

AA battery current

For some reason whenever I play with a multimeter it always gives me results I never expect. In this case I am attempting to measure the current of a AA battery. I have the multimeter set to 10A on ...
0
votes
4answers
44 views

Redirection of electrical current

Sorry if this is about the newbiest question on this site, If I were to draw a graphite trace on a piece of paper (which from what I know would have some amount of resistance), and connect a ...
0
votes
1answer
54 views

Strange current reading, LED's in series

I have a 19.4v/2.37A power adapter. I have 5 LEDs (3.2v-3.4v 20mA) connected in series. When I measure the current, the reading says 0.08A, which is total of 4 LEDs, not 5, but close enough. ...
0
votes
0answers
32 views

DC Variable power supply fluctuating? (ATTiny85)

I hooked up an ATTiny85 to my computer using an avrisp programmer, with a red LED on PB3, a 4.7k ohm pull-up resistor on reset, and a 180 ohm resistor in series with the LED on pin 3. I was able to ...
-3
votes
2answers
75 views

How to make ammeter with arduino?

i'm interested to make ammeter from arduino. So, i have 70A/50mV shunt resistor and wiring it into arduino. From my schematic, Is this possible to meassure the current from 12V battery?If it possible ...
0
votes
0answers
35 views

voltage drop when probing a NPN transistor's emitter to collector, collector to emitter for PNP

I have some old 2SD1785 and 2SB1258, NPN and PNP transistors that I pulled off of a car audio amplifier. Using this site, I tested the transistors in question and find that they fail on the test on ...
0
votes
1answer
102 views

Why did sparks fly when testing outlet frequency?

I'm using a multimeter (Mastercraft 052-0052-2) and I decided to see if the frequency of an outlet would read 60hz. I switched my multimeter to the FREQ setting and plugged the RED test lead into the ...
3
votes
3answers
189 views

Why isn't Ohm's law working for this simple circuit?

I have a 70W 12V-500V DC power converter, and something in these pictures is not adding up. I run the 500V output through a high-voltage 332kΩ resistor. Now, using the left multimeter I ...
3
votes
3answers
166 views

What is the peak - peak voltage of 15mV rms white noise?

I've been experimenting with zener diode based noise sources. I have such a source for which I want to determine the peak to peak noise voltage. I've measured the noise with my trusty multimeter and ...
-1
votes
2answers
86 views

How do I identify a burnt out component? [closed]

I was given a project completed by another group, they had left school and I was taking over the project from them, with the information that it is not working properly because "something burnt out or ...
0
votes
1answer
53 views

Calculating resistance with a multimeter

I recently took on the job of working on someone's amplifier. There was a burnt smell coming from it. I found the pieces of the puzzle that were fried and replaced the ones I could, two diodes and two ...
1
vote
1answer
54 views

Calibrating a multimeter without another multimeter

I have a hand-me-down multimeter from my Mom made in the 80s. I don't have another meter that is good enough to be used as a calibration standard, however I do have a few reference chips and precision ...
2
votes
1answer
39 views

How to measure resistance across a capacitive load using an Agilent 34410A in GPIB mode

I'm trying to measure resistance across two test points in a circuit that has an overall capacitive load. This is for a very specific application and it is to ensure there are no shorts in the ...
29
votes
10answers
5k views

Multimeter exploded during ACV measurment - What did I do wrong?

simulate this circuit – Schematic created using CircuitLab A DT-830B meter. I bought a new transformer, and I was trying to measure the output voltage. I plugged the probes on 'VΩmA' ...
1
vote
1answer
169 views

Have I damaged my multimeter by applying voltage in resistance mode?

I have an VC97 digital multimeter. In resistance mode, I applied the multimeter leads to a battery with a 4.2V charge. I did this twice, and also did so in capacitance mode. I didn't notice any ...
0
votes
1answer
93 views

How to measure a BC-547 transistor's details?

I am new in electronics. What I am trying to do is measuring everything of BC-547 transistor's details from a basic circuit design practically. I want to measure as example: collector-emitter ...
0
votes
1answer
39 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
98 views

How Cheap AC Clamp Meter Reading on DC Current? [closed]

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
3answers
138 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
66 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
83 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
200 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
73 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
93 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
91 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
881 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
357 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
234 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
113 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
157 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
91 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
185 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
259 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
881 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
128 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
718 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
173 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
79 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
283 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
155 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
80 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
75 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
141 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
206 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
89 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
1k 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
63 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). ...