Measurement is the assignment of numbers to objects or events. All measurements consist of three parts: magnitude, dimensions (units) and uncertainty.
Questions tagged [measurement]
1073 questions
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votes
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Can an oscilloscope be used as an EKG?
I was at my doctor's office and noticed an EKG machine that looked like a standard oscilloscope. In fact, its case was almost identical to my dual channel Tektonix 1104b. The main difference was that it had more probes, but I didn't check if they…
user148298
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Help learning from a mistake connecting an oscilloscope
I have built this circuit to dim a lamp with a PWM signal. It had an issue where the MOSFET was getting really hot. So I wanted to know what was happening on the gate of the MOSFET.
I turned the PWM signal off and with my multimeter I measured…
cyrili101
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Level of a water tank with a microcontroller
How do i measure the level of a water tank with a microcontroller?
mad_z
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20
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Why is this meter giving different readings depending on its orientation?
My newly-restored (re-capped) 1950s vacuum tube voltmeter is now operational...but there's one further issue. The meter gives correct readings when lying on its back, but when oriented vertically- as I'd like to use it - the readings are wrong and I…
Simon Owen
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Why only sine waves?
I have already read a few EE texts where a sine wave is often seen.
Why is the sine wave often used as a test function for a circuit or a system? Why don't we use any other signal instead of sine?
Do we use sine waves as test signal because of the…
LECS
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How can I measure the temperature wirelessly inside a piece of meat?
For a cooking experiment, I'd like to be able to measure the temperature inside a piece of meat while it's being cooked. Due to the mechanics of the cooking process, it's going to be difficult to use a wired temperature probe, so I was wondering if…
Rocketmagnet
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How does the network card determine the cable length?
I have an older Gigabyte Technology GA-MA770T-UD3P motherboard with an on-board network card described like this:
Model: "Gigabyte Onboard Ethernet"
Vendor: pci 0x10ec "Realtek Semiconductor Co., Ltd."
Device: pci 0x8168 "RTL8111/8168/8411 PCI…
U. Windl
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Why are oscilloscope input impedances so low?
My question is two-fold:
Where does the input impedance come from?
I'm wondering where the input impedance of your average multimeter or oscilloscope comes from? Is it just the input impedance to the device's input stage (such as an amplifier or…
PersonWithName
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Why do digital scopes sample signals at a higher frequency than required by the sampling theorem?
In the quest for a not so expensive PC scope/logic analyzer, I have found a nice little device it looks very well done and I know it will do the job.
However looking at the specifications, I encountered this:
Bandwidth vs Sample Rate
In order to…
LuisF
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How do I measure differential signals (like RS-485 or DMX) on an oscilloscope?
I've encountered differential signals in a few places, such as a differential output audio amplifier and now in a project working with DMX which is similar to RS-485. (Here's a similar question about RS-485.)
Looking at a waveform from a DMX…
JYelton
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17
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7 answers
Physically determine unknown wire's gauge
Is there any way to easily and accurately determine the gauge of stranded wire by measuring it?
I know you can pretty easily determine the gauge of solid-core wire with just a pair of calipers by measuring the conductor diameter, but with stranded…
Connor Wolf
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What kind of oscilloscopes are qualified for measuring USB 3 Super Speed Signals?
I understand that they probably will be very expensive. But I have little idea of what kind would qualify. How much bandwidth? At what sampling rate? Any other parameters?
J.L
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Ways to determine polarity (dc) without a meter
I came across this question about how to figure out the polarity of a cell phone charger without a meter. This made me think of what methods you could use to figure out the polarity other than using a meter or any device that is better than a meter;…
Garrett Fogerlie
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How do you calculate the noise of an op-amp circuit?
I think I know how to do this, but you can find a lot of different instructions and calculators online that contradict each other. I have yet to find a clear, concise procedure for calculating the self-noise of op-amp circuits (including thermal…
endolith
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Why am I getting odd inductances from home made inductor?
This question is related my my previous question: What to do about very hot planar inductor?
What I'm trying to do
I am trying to make a planar inductor (made from the tracks of the PCB, and surrounded by a 2 part a ferrite core). According to the…
Rocketmagnet
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