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Questions tagged [multimeter]

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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1answer
248 views

Power supply requirements for TM355

I've recently got hold of a second hand Thandar TM355 bench multimeter. It can be supplied by either 6 "C" cells or there's a 2.5mm barrel plug for power. Unfortunately, the service manual doesn't ...
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3answers
537 views

Resistor before voltmeter

Let's say I take my multimeter and measure the voltage across the poles on my battery, I get some reading X volts. I then put a resistor between one terminal and the adjacent probe, this resistor has ...
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5answers
2k views

Why do DMMs have a capacitor on their AC measurements?

see answers to this question. Is a capacitor really necessary? And wouldn't it make measurements frequency-dependent?
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6answers
18k 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) ...
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3answers
5k 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 ...
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2answers
8k views

How to wire a GSM module to my alarm system

I have an alarm system that has been installed by an alarm dude ;) I want to add a GSM module to the alarm system, so that I'm notified when the alarm is triggered. Before I purchase the module I ...
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3answers
749 views

Multimeter misuse by shorting a 220 voltage through it

I intended to measure an AC voltage, but I forgot the multimeter on the resistance position (200 Ohm scale). I've shorted the 220V through the multimeter. The fuse is not damaged, neither the bridge, ...
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1answer
1k 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" ...
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1answer
15k views

Why does my multimeter's overload indicator come on during normal use?

I have a new digital multimeter (Kopp GCM-620) that has auto ranging, and an overload indicator on its LCD. When testing a mains outlet (the voltage where I live is 230V), the LCD shows a reading ...
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2answers
1k views

Impedance of microcontroller pins with no power supplied?

I have a serial flash chip connected to an ARM microcontroller (AT91SAM9G20). I'd like to be able to program the serial flash after both chips are soldered on to the PCB. For each of the serial flash ...
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2answers
6k views

How to test for ground loop using multimeter?

I am experiencing a hum in my audio line from my computer. I suspect it's from a ground loop. My monitor (which house the speakers) is a 2 prong plug is plugged into a separate outlet from the power ...
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2answers
941 views

How do I measure impedance of my guitar pickups?

How would I measure impedance of my guitar pickups with a multimeter? Is it similar to measuring resistance?
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1answer
1k views

General PSpice and 555 timer question regarding precision

I have been experimenting with values recorded using a multimeter versus the voltages (RMS) simulated using capture. I simultaneously setup a circuit using a breadboard and drew exactly the same ...
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3answers
39k views

What does it mean when multimeter accuracy is marked as: ±0,03%+10Digit?

I have a digital multimeter and its accuracy for VDC is marked like this: ±0,03%+10Digit This multimeter has maximum display of 80000. So in the 80 V range it can show for example 79.999V. 0.03% ...
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2answers
372 views

How stable are digital multimeters' parameters?

I live in a region where standard mains voltage is 220 volts. Recently I tried to measure it using a digital multimeter. The multimeter specs say that it has maximum error of 1,2 percent of the ...
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2answers
14k views

Can I Test Bug Zapper's Voltage With Multimeter?

I have The Executioner bug zapper: Although it uses 2 AA 1.5v batteries, it also has voltage multiplier like Cockcroft–Walton generator i guess and would like to know if it is safe and would make ...
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3answers
726 views

Touchscreen DMM Development Board

I think one day soon, if not already now, somewhere, there will be Multimeters that have touchscreens and are software configurable with Apps that allow you to add most anything to your meter like an ...
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4answers
6k views

Fuse blowing in 12 multimeters rated for 200mA, only measuring 12.5mA. Why?

I'm a high school electronics teacher and while doing a lab on Ohm's Law we just blew the fuses in 12 out of 18 brand new digital multimeters while measuring current, and no the meters were not hooked ...
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4answers
5k views

What should I expect the low end of my multimeters resistance measurement range to be?

I have an old Fluke 79-III and I'm trying to check the resistance of some resistors which should be 0.22 Ohms. Unfortunately, they are all reading 0.6 Ohms and so I'm wondering how accurate I should ...
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1answer
454 views

Communicate PIC with digital scales/DMMs

Is it possible for anyone to make a PIC(I'm thinking of using 16F628/16F628A) communicate with another device, in this case a digital scale or industrial digital multimeter using USART/serial port ...
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3answers
16k views

Beginner question about measuring current using digital multimeter

I have a beginner question about using multimeter to measure a current. I have dc motor, attached to 2 x AAA batteries. Which reading I should use, 200 m under DCA or 2000 mA? On 200 m, the current ...
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2answers
352 views

Why do multimeters show values at the lower parts of a given range the way they do?

Suppose I have a 20,000 counts multimeter, and I am measuring a 220k resistance with it. The multimeter can only display a resistance below 200k as 200.00k - ...
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4answers
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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 ...
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5answers
49k 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 ...
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2answers
2k views

is it possible to repair a DMM which was burned by putting the leads into 230V on a frequency-measuring setting?

There is a DMM (not a cheap one, so its worth to repair it), whose leads where put into a 230V AC socket on the frequency measuring range. The meter did "bzzzt" sound and stopped showing anything. ...
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2answers
5k 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 to ...
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3answers
930 views

Will current flow through my digital multimeter while it is powered off?

I've just got a cheapo < $20 digital multimeter here and was curious if anyone could tell me whether current might still flow through it after i turn the dial so that the power is off. Some ...
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1answer
2k views

Is there a USB interface for a RadioShack 22-812 Digital multimeter?

I have a RadioShack 22-812 Digital Multimeter which has a Serial PC Interface. Is there any sort of adapter that I can use to connect it to a computer's USB port instead of using the Serial Port?
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8answers
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How to measure gigaohm resistors?

I've got an issue that appears to be caused by damaged resistors that are either open circuited or of too low a value due to contamination. The problem is that they're gigaohm resistors, so to a ...
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1answer
761 views

Can I burn out my multimeter's µA range by using a few mA of current?

My multimeter only has one 400mA fuse protecting the µA and mA range (and a 10A fuse protecting the amp range.) Is it possible to damage the microamp range by feeding milliamps through it?
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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 ...
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2answers
1k views

What Ways to Calibrate a Multimeter?

How can one calibrate a multimeter, like a UT61E or any other multimeter in the 50 ~200 $ pricemark, when one does NOT have an expensive FLUKE nor a friend who has a FLUKE)
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327 views

Can anyone suggest a voltmeter that can do the job? [closed]

I am trying to make a high voltage measurement on an industrial sputtering machine. The voltages are in the 50V to 1000V range. Right now, we're using a Fluke DMM because we need a true floating ...
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4answers
752 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 ...
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2answers
3k views

How to calibrate multimeters?

Without buying an expensive calibration tool, how can I accurately calibrate my multimeters?
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1answer
42k views

How do I measure the voltage coming out of a USB port?

If I attach a USB cable to a USB port, and then strip the wire at the end, then how do I connect a multimeter to it to measure the voltage?
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Is it worth really buying a Fluke for hobbyist use? [closed]

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 ...