Measurement is the assignment of numbers to objects or events. All measurements consist of three parts: magnitude, dimensions (units) and uncertainty.

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Which one is more accurate: Digital oscilloscope or Analog oscilloscope?

I know it is some sort of wide question, but nowday I usually only see digital oscilloscopes around. I want to know if their digital nature will affect the accuracy of measurements? (Something like ...
2
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1answer
42 views

Method and probes for measuring resistance of conductive braiding?

Looking for advice on a method to measure the resistance of a piece of conductive braiding. The braiding is a metal plated material; it's flat when pulled taut and expands into a cylinder when bunched ...
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40 views

Arduino piezo vibration measurement circuit

I'm looking for a very simple measurement circuit to measure vibrations with a piezo elment and an arduino device. I want to read positive and negative values. I have this sensor: ...
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1answer
34 views

Piezo vibration sensor board negativ values

I have this piezo vibration sensor module from Grove: http://www.seeedstudio.com/wiki/Grove_-_Piezo_Vibration_Sensor Using this sensor and an arduino device I want to measure two things: amplitude ...
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19 views

the best book to practice [on hold]

I am looking for a book that would let me practice the chapters of Principles of Measurement systems by John P Bentley. I am looking for a book that has all the contents of the this above mentioned ...
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1answer
37 views

What means linear response for accelerometers?

What means that accelerometers measures linear acceleration and, in particular, that they are a linear response?
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59 views

Low noise amplifier

Recently, I got a low noise amplifier (i.e., ZFL-1000LN+ from MiniCircuits, http://194.75.38.69/pdfs/ZFL-1000LN+.pdf) with two wires already soldered in the turrent terminal pins. Today I have been ...
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2answers
63 views

DIY DC Blocking Capacitor for oscilloscope

I'm studying switching converters and want a bench setup that will allow me to reliably observe the various voltage waveforms (output, inductor, switch) on my oscilloscope. I discovered pretty ...
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1answer
63 views

Questions about Dry EEG electrode interfacing circuit

I have finished reading a paper about developing an interfacing circuit for Dry EEG electrodes and there is a few points that I couldn't understand. To mask the diode’s parasitic capacitance and ...
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2answers
84 views

How to measure speed without any mechanical or electrical connection?

I would like to build an as-much-portable device for measuring the speed of a vehicle, to check speedometer accuracy and know the offset if one present. The idea is a cigarette pack sized box one can ...
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1answer
87 views

human weight scale (60-180kg) with gram resolution [closed]

Is it possible to create a scale with a dynamic range of 5-6 figures? (measure the weight of a person in a gram resolution)? If not why? If yet, how?
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45 views

grounding measurement methods

As long as I know the accepted methods for measuring the resistivity of electric grounding grids, once they are built, for any kind of building (in cities, at industrial level, transmission towers, ...
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1answer
37 views

How does capacitive EEG electrodes measures EEG signals

I have read the following sentences from an article: The effect that there are also charge displacements on the body surface due to brain activity is used for the capacitive measurement of the ...
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2answers
28 views

Where should I look for transformer inductance discrepancy?

I'm experimenting with this smallish (~15VA) toroidal line transformer as a "lab" exercise as I'm learning about transformers. Right now it has its original 115V primary winding only; I "unwound" and ...
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1answer
77 views

Design challenge: Detect finger-to-finger touch with nothing in between

I'm trying to build something quite challenging and seem to be getting nowhere. Maybe you'll help. I'd like to detect a touch of two naked fingers with no materials or sensors in between (simple ...
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1answer
44 views

Expanded standard deviation in logarithmic scale [closed]

Hello and good day to all. Referring to picture attached I have a question. . I am working on different measurements and trying to find the mean and standard deviation values of these ...
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0answers
20 views

How to measure complex permittivity of a capacitor?

Armed with the relevant theory, I would now like to actually measure the complex permittivity of a capacitor. Can I do it using a simple RC circuit? For example: Use a scope to generate a signal ...
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2answers
116 views

Questions about sound card scope software?

This is a popular software for those people who don't have a real oscilloscope or function generator: https://www.zeitnitz.eu/scope_en If anyone tried it before, would you answer my questions, ...
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0answers
44 views

How to properly store big values in parallel SRAM

For a project I need to determine the frequency and phase-shift of up to 16 channels. The frequency range is 0 to 3 kHz and the signalform is square. My first idea was to use the following circuit ...
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0answers
18 views

Ways to improve saturation time in Multiplexers

I'm using max4708 multiplexer (operated as single supply 36V), when i tested the multiplexer- my inputs, for example +32V, +20V get well saturated at 20Khz.Later when i added to the circuit, for the ...
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2answers
53 views

Heatsink temperature probe

I read around that with an anonymous heatsink, you can measure its temperature when at regimen dissipating P watts. Then, (T-Tamb)/P gives its thermal resistance. Is that meaningful? Can I do this ...
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1answer
78 views

Calculate Distance via phase shift

I see through phase shift we could calculate the distance. This is the principle inside laser rangefinder as well. But for this equation, I still do not know how it is derived. $$ D=\frac {c* -1* ...
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1answer
41 views

whats the right kind of reference to calibrate a measurement instrument?

I have been working in a calibration system for a multimeter I'm developing To do this i'm calibrating the reading values using Fluke meters (bassically my instrument has to match the fluke ones) ...
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1answer
48 views

VGA levels, why are they wrong?

I read everywhere on the Internet that voltage levels in the color components of a VGA cable should go from 0 V (dark channel) to 0.7 V (maximum brightness for that channel). However I tried to ...
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2answers
83 views

Variable frequency AC power source

I'm looking for a variable AC power source for use in some electromagnetics experiments and longer term for testing inductors, transformers, core material frequency response, and that sort of thing. ...
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1answer
63 views

Noob Measurement Mystery

I am taking up electronics and bought some used test equipment. I have been measuring anything and everything, sometimes with unexpected results. Above is one of those cases. The function generator ...
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3answers
103 views

Oscilloscope measuring different voltages “across” the components when two probes are used

I'm having problems displaying two channels simultaneously on an oscilloscope when both probes are connected to measure voltages "across" the components. To demonstrate the problem two resistors are ...
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2answers
34 views

HP8116A Function Generator Signal Problem

I'm trying to use a function generator HP 8116A and an oscilloscope Tektronix TDS210. When i connect the probe to trigger output of function generator, i can observe the square wave correctly. ...
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1answer
64 views

How do you get from experimental measurements to models?

Many analytical models in the literature are "based on empirical measurements". For example, for a radio propagation model, one would go out in the field, take his equipment and perform a lot of ...
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30 views

Getting the DC current in dV/dI circuit

I have a simple circuit: R1, R2 and R3 are actually one sample that has 4-terminals. The series resistor is to ensure current-driven mode. The voltmeter and Ammeter are actually Lock-In amplifiers ...
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1answer
50 views

Measuring voltage window with ADC

I'm working on my own SLA charger that has MCU onboard, can regulate switching DC/DC converter to charge 12V battery in 3 stages and can do temperature correction. Everything is fine except that I ...
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3answers
987 views

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?
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3answers
51 views

Term for errors that are constant for a measurement

In my measurements, I am encountering errors that remain constant over a measurement but change from one measurement to another. The errors specifically are amplitude and phase errors resulting from ...
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1answer
84 views

Measure resistance value between all nodes in a 3x3 resistor grid

I have a Schematic like that: (except the power supply is an Arduino Uno with a voltage divider to measure resistance between any pair of ABC and 123, except C3 of course) How can I get the ...
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1answer
29 views

NTC error propagation: what I missing?

Reading through a Vishay datasheet of a NTC, I found the guide to devise the temperature error: I don't understand why the errors of X and Y, for the non-approximated formula, were multiplied ...
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3answers
60 views

distance measurement open circuit

I'm currently working on a project where a sliding metal box is mounted on a metal pole. The box moves up and down. At the top of the metal box is a small processing unit that needs to know the ...
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1answer
71 views

Testing parallel IGBT module

A single NPN IGBT chip can usually be tested by a 9V battery between gate and emitter. However opening up a larger module reveals many IGBT modules in parallel. I`ve seen some inverters using ...
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23 views

crypto benchmarks STM32L4

Can someone give me an indication on the performance (time) of ECDH executed on the STM32F4 board. The STM32F4 has hardware acceleration for ECC ...
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2answers
152 views

What's the most economical way to digitally measure 240V mains voltage, current and power factor?

I'm looking to capture and analyse measurements of the mains energy that I use per circuit. I've found a few consumer products that offer powerpoint energy monitoring such as the Kill-A-Watt, but PC ...
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2answers
76 views

Choosing a Shunt Resistor for Low Current Applications

Is it possible to use a shunt monitor to measure current for low values(10 mA-100mA) and if is it possible, should I use low resistive values like in most of the power circuit applications? I know ...
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3answers
117 views

Non-linear scale of ammeter? [closed]

Recently some one asked me 'Why ammeter (based on moving coil principle) has a non-linear scale?' In multimeters (not based on moving coil principle) which we uses in digital lab, I didn't found any ...
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2answers
392 views

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 ...
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1answer
67 views

How to measure parastic capacitance of a trace

I have a 24 MHz, crystal on my board and datasheet of IC defines the load capacitance between 5-9pF. The reference design I follow don't use any load capacitor. My traces look like this: shorter ...
3
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1answer
166 views

How can I use an oscilloscope to measure voltages that are referenced to nodes several hundred volts apart?

In my organization, we often use four-channel oscilloscopes to check out products. Each probe reference might be several hundred volts away from the others, which makes using standard scopes ...
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0answers
44 views

What is the accuracy of a thermocouple after calibration?

I'd like to use a thermocouple to create a general-purpose temperature probe. However, the accuracy is quite a bit lower than I want. Almost every source I look at (example) lists the accuracy of a ...
0
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0answers
58 views

How to convert a signed difference of potentials to an unsigned voltage referenced to ground with a single supply?

I would like to use the ADC of an Arduino as a voltmeter, however the only power supply available is 3.3V, and I would like to measure differences of voltages (not potentials) up to 30V with an input ...
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1answer
66 views

arduino current

I want to start learning EE with Arduino so as a project I decided to build an Ohmmeter and measure a (specific) resistance that should be about 100 KΩ ±50KΩ. In order to probe for that resistance I ...
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1answer
87 views

High resolution resistor measurement technique

I'm working on high resolution resistor measurement system. I need to detect %1 and %5 tolerance difference. Now I set the system typologies like pic1 via analog multiplexers.(ADG708, ADG732) R1 is ...
4
votes
3answers
105 views

How to check if a DC power supply is a floating source?

Imagine a laptop power supply with 2 prongs and I'm using this as a power supply for a circuit, and the output of this circuit is an input signal Vin for a data acquisition hardware. How can I ...
4
votes
1answer
159 views

Resistor wattage measurement

I'm not an engineer professionally but I'm interested in. So my question is, how to recognise the wattage of a resister? And how to measure it using multimeter?