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.

Filter by
Sorted by
Tagged with
1
vote
2answers
121 views

What informations can we obtain with these voltage and current measurements of a little electronic device?

I powered a little electronic device with 2 AA batteries and here are the results measured with a multimeter: When using a first set of 2 AA batteries: Voltage when device unplugged: 2.45 V Voltage ...
0
votes
0answers
29 views

Booting up a Lomvum T28B multimeter!

I have the above mentioned multimeter; I know this seems trivial but I'm new to this how in the world do I switch it on. There is no indication in its manual of where the power button is. Am I missing ...
0
votes
0answers
64 views

Automated multimeter [on hold]

I want to use automated digital desktop multimeter for making around 30 measurements in period as short as possible and transfer this data to my PC and later on use LabVIEW or make my own test ...
0
votes
2answers
104 views

Why does the measured current differ from the calculated current in this circuit?

I have the following schematic: Now I want to know the (more or less) exact current flow in my circuit. For this I did the following calculations: I = V / R I = 5V / 330 Ohm I = 0.015A = 15mA So ...
0
votes
3answers
70 views

Will multimeter show a voltage in an electric field?

I think that it won’t because there is no current entering the meter with which it can measure. Correct? Also, is it the same reason why the meter won’t show a reading even though one probe is in air ...
0
votes
1answer
39 views

How to insulate more of my fluke test leads [closed]

these are the test leads I own, I am wondering if there is a something I can purchase to shield the exposed metal more to avoid incidents. I heave the little plastic shield that comes with them but ...
0
votes
2answers
95 views

How much current does this read?

How much current is flowing here?
2
votes
2answers
101 views

How can you damage DMM if you haven't discharged a capacitor?

Hi, I measured capacitance on some capacitors using my UNI-T 139S True RMS Multimeter without discharging them first. To be clear, I don't even know if they were charged because they are mounted on ...
2
votes
2answers
34 views

Reading voltage from coil on top of Qi Wireless Charger

I am a high school student doing a lab report on changing the number of turns of a coil and seeing the effect it has on the output voltage from a wireless charger. I am trying to take a Qi Wireless ...
0
votes
3answers
83 views

Can I make a ammeter using a voltmeter and ohmmeter that would work in parallel to the device?

I had this small question today when working with an ammeter. Since an ammeter must be in series of the circuit, I had to constantly break the circuit to take current readings. Whereas, when using the ...
2
votes
2answers
470 views

How do we test and determine if a USB cable+connector is version 2, 3.0 or 3.1?

How do we test and determine if a USB cable+connector is version 2, 3.0 or 3.1, without using port, PC and/or having data transfer but instead with basic physics tests e.g. using multimeter?
1
vote
2answers
74 views

Two different LED types: diode test on two different multimeters shows just “1”

I have two multimeters - granted, they're both the super cheap DT830B types, but slightly different models and one is straight from the packaging. I also have two bags of LEDs - bright red and bright ...
0
votes
1answer
44 views

How could I measure RF transmission power from SMA connector without having a RF wattmeter equipment?

I need to measure the RF power of a radio transreceiver, and since I haven't specific RF wattmeter equipment, I'm wondering how I could do this using a classic multimeter. I would avoid to ...
3
votes
3answers
119 views

How does multimeter AC measurement work?

How does a digital multimeter measure AC voltage? My guess would be that the AC voltage is rectified and filtered into a DC voltage which is then measured, giving the peak voltage of the AC signal. Am ...
0
votes
0answers
33 views

Is there a way of measuring components in circuit? [duplicate]

I have some old circuit boards full of SMD components that I would like to reuse in my projects. Before going through the trouble of removing any from their old circuits, I would like to know if they ...
14
votes
5answers
5k views

Why isn't there any 9.5 digit multimeter or higher?

Why can't you buy a 91⁄2-digit multimeter? Isn't there any need for it? Is a 81⁄2-digit multimeter the latest high end you can buy? I have tried Keysight, Keithley, and Fluke, but there is nothing ...
0
votes
1answer
94 views

Multimeter seems to be giving incorrect mA reading [closed]

I'm measuring the current drawn from the negative battery terminal of my car battery. I am not sure if the correct reading is 0.16 A or 1.6 mA. I tested with my multimeter on both 10 A and mA ...
2
votes
5answers
1k views

Am I testing diodes properly?

I decided to test some diodes that I have, using a multimeter to measure their forward bias voltage. I set my multimeter to voltage test and connected the diode across: I tested a bunch of different ...
0
votes
1answer
67 views

I want to measure 50 miliamps by multimeter which range i should select?

I have a multi meter I want to measure DC 1-50 milliamps which range I should select by the knob? Also where I need to plug in 20A or mA?
2
votes
1answer
95 views

Discharging capacitors with a multi-meter in diode mode

Recently I encountered this "trick" where you use a multi-meter in diode test mode to discharge a large electrolytic capacitor. I feel that this cannot be a good practice, but the people who were ...
0
votes
1answer
56 views

How to check (6 pin) PCI-E power rail on a pc powersupply?

Could anyone tell me if and how i might verify whether or not a PCI-Express 6 pin power lead on a PC is outputting correct voltage(s) ? A while back, I decided to try to refurbish a graphics card ...
28
votes
5answers
3k views

What does the multimeter dial do internally?

Everyone who has ever handled a multimeter is familiar with these dials. The position of the dial indicates the maximum range of the quantity that can be measured. But why are we required to adjust ...
1
vote
3answers
101 views

Measure 10kV with 600V rated multimeter [duplicate]

My multimeter is rated for 600V but I need to measure a 10kV AC source. I was thinking of building a voltage divider but I wouldn't know how many resistors it would take to safely measure this high of ...
0
votes
2answers
172 views

How to test a TRIAC with just a digital multimeter and no external circuit

I need to fix an electric kettle and would like to test the health of the TRIAC BTA20. How would you test this component health with a digital multimeter - without any extra components and ideally ...
1
vote
1answer
98 views

Why am I reading 22VDC / 69VAC when measuring between myself touching a MacBook and ground?

If I put the positive probe of my multimeter on earth, and touch the negative probe with my hand, while another hand is touching the metal surface of my MacBook, I get around 22VDC or 69VAC. I cannot ...
5
votes
1answer
192 views

Why so much variance in the continuity beeper threshold? How do these beepers work anyway?

In this answer it is mentioned that the EEVBlog-branded BM235 meter has a threshold of between 30 and 480 ohms for its continuity beeper (as seen on page 25 of the datasheet). My first thought was "...
8
votes
3answers
1k views

Is the continuity test limit resistance of a multimeter standard?

The continuity shows us the shorts, but many times I guess, even if the wire has a resistance of up to 50 ohm, the continuity will beep to indicate a short. Is it always 50 ohm, or what parameter ...
0
votes
4answers
84 views

Solar cell outputs full voltage but barely any amps

So I've asked a similar question in the past, but I'm still curious about something. On a fully sunny day, the solar panel tops out at 5.5v @ 260 mA. On overcast or cloudy days, the voltage stays ...
1
vote
3answers
187 views

How do digital multimeters measure capacitance?

How do digital mulitimeters (DMM) measure capacitance through their typical 10M Ohm input/output impedance? Providing a logic level of 3.3V, attempting to measure 1F would mean a time constant of ...
0
votes
3answers
78 views

What does DC voltage reading from a DMM mean?

When a DMM is set to measure DC voltage, does a read-out value correspond to an output of the ADC inside the DMM, or do multiple ADC outputs are averaged over a time interval and then converted to the ...
-1
votes
2answers
68 views

multimeter, current measurement (beginner)

From this little circuit I try to calculate the current for Ic, Ib, Ie. For Ic , I put the multimeter on 20mA and positive wire connected to 10A and I got 0.01 ... 10mA ? for Ie it is the same (Ie = ...
0
votes
3answers
40 views

How to measure current in very low duty cycle circuit with DMM?

My circuit has 4Hz 50% duty cycle. How do I measure the average current using a DMM? I have a Fluke 87 DMM. It has an average setting but for 100 ms which less than one complete duty cycle. My ...
0
votes
0answers
59 views

Why is there a positive body voltage when grounded, but none when not?

So after reading about earthing and earthing mats, I decided to make myself a very basic one for cheap to test the concept before jumping in with purchasing more sophisticated products. Here's what I ...
0
votes
1answer
66 views

How do I find the right resistor for an LED panel? [closed]

I purchased one of these cheap LED panels to light a room. One review suggested that it's important to put a resistor on it, to keep it from frying itself. But, he didn't list what resistor to use. ...
1
vote
1answer
73 views

LED intermittently fails but works when voltmeter applied

I have an LED in a home project. It's in a simple loop with a resistor and the GND and V+ ends connected to appropriate pins on a microcontroller. The LED works properly for extended periods of time ...
1
vote
2answers
64 views

Diode meter of my DMM does work for red LEDs but not for white LEDs

I have a diode meter on my DMM Powerfix Profi and I want to measure the forward voltage. (actually it is not so profi at all). So I tried the steps needed, and found the Vforward of a red led to be 1....
0
votes
1answer
114 views

Resistance reading on digital multimeter

I'm working my way through a beginners electronics book (to be specific it's 'Starting Electronics' by Keith Brindley). I've got up to the second chapter which introduces resistors and their colour ...
0
votes
5answers
155 views

How can a multimeter measure current while being parallel to the element

An ammeter is a low resistance device connected in series with the element through which we want to measure current However, a multimeter is connected in parallel with the element under observation ...
0
votes
1answer
219 views

Can I use a multimeter to measure audio signals by testing amperage or voltage?

I'm in the process of adding a subwoofer to my car. In doing so I spliced in a T harness to audio wires from the head unit and routed the wiring to where I Will be placing the Amp. I tested the ...
1
vote
3answers
89 views

powering an old 9V multimeter with a 6x AA battery pack

I have an old Nimex NI2100 multimeter that is working fine with 9V batteries. Btw i'd like to power it with 6x AA batteries instead so i've bought a battery holder and wired like this: I've checked ...
1
vote
1answer
175 views

Why do two different multimeters show completely different resistance readings?

I just received a brand new Brymen 869s and I'm concerned it may be broken as it's giving a strange reading. When measuring a 100k 0603 resistor which is soldered into a PCB (forming part of a ...
0
votes
1answer
82 views

Ammeter scale, not sure what my amp reading is

I have a basic multi-meter that I am using to measure amp on a load. I am trying to figure out how much amps my small entertainment system draws. (LCD TV, PC, speakers.) I want to build a small DC ...
18
votes
3answers
2k views

Determine voltage drop over 10G resistors with cheap multimeter

I have two 10G resistors connected in series with a 3V battery. I want to determine the voltage drop across one of them, which of course is 1.5V. When I use my multimeter to check the voltage drop, it ...
0
votes
1answer
61 views

Measure voltage of the panel light bulb inside a vintage radio

I'm new to Electronics. I have recently received a vintage radio Pioneer TR-305. I am trying to replace the panel light bulb inside this radio. I opened the radio panel and found the bulb soldered ...
0
votes
1answer
104 views

Wheatstone Bridge - strain gauge sensor

I'm trying to optimize a Wheatstone bridge with a strain gauge sensor and I'm considering all possible wire resistances. The circuit is shown in the following figure: I don't understand the comment ...
0
votes
2answers
134 views

How to use a multimeter to test the resistance of my tongue?

I just purchased this cheap-o multimeter: https://www.amazon.com/AstroAI-Digital-Multimeter-Voltage-Tester/dp/B01ISAMUA6/ref=sr_1_1?keywords=astroai+am33d&qid=1551837071&s=gateway&sr=8-1 ...
-3
votes
1answer
72 views

Multimeter Giving Wrong Temperature Probe Readings [closed]

I want to ask a question about my multimeter, it's new but when i plug in the temperature cable - red to VOhm, black to COM and turn to tempreture it displays temp of period(-886°C/-900°C), and when i ...
0
votes
1answer
60 views

Circuit Failure How to fix it? [closed]

I'm sorry I am very specific here, I have a problem with the charger of my motorbike dashcam and I hope you can help me fixing it (see picture and video test with multimeter). I really have no idea ...
0
votes
1answer
178 views

Display input from multimeter on PC [closed]

I have opened a Multimeter (Model:DT830D) and I want to take the input that is fed to the LCD display and display it on my PC instead using the serial monitor of the arduino. But I am confused about ...
0
votes
3answers
141 views

multimeter temperature accuracy [duplicate]

I have tried searching for an answer and looked online, but I'm just getting more confused. I have a DMM that measures temperature with a thermocouple lead, with a resolution of 1 degree C (shows 020)...