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Questions tagged [measurement]

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

2 votes
0 answers
82 views

What are the disadvantages of crocodile (alligator) probes? [closed]

When measuring with an oscilloscope, I use an original high frequency oscilloscope probe and a double side crocodile (alligator) clip and the results are usually very close. Note: it is called ...
2 votes
1 answer
74 views

How to measure Lithium-ion battery SoC?

I have a 48 V 12 Ah Lithium-ion battery pack. I am struggling in finding a way to measure its State of Charge. It will be charged through a 13S JBD BMS. I need to spit out information from the battery ...
1 vote
1 answer
315 views

HLW8032 energy meter circuit showing power usage at no load

I am designing an AC energy metering circuit. The circuit has to measure voltage, current, power, power factor and energy used for two channels (from the same source). The HLW8032 transmits 24 bytes ...
0 votes
1 answer
143 views

How to calculate frequency of an AC source with variable frequency using Arduino

I have an AC current source. Its properties are Maximum Vrms=15v Maximum Frequency 125 Hz Minimum Frequency 5 Hz The current source is pickup coil of a motorcycle... Vrms range is approximately 0.7v-...
0 votes
1 answer
49 views

How to Read Unipolar Square Waves on TRMS Multimeter

I'm trying to switch from reading my high-voltage unipolar square wave signal from a benchtop oscilloscope to a handheld multimeter, but I don't understand why my multimeter is giving the voltages it'...
0 votes
1 answer
166 views

differential measurement vs ground

I am looking to measure an incoming V vs ground with an ADC (MCP3424 or equal). The Vin vs Gnd can be anywhere from -1.5V to +2.0VDC. I looked at using an op amp with level shift, when I came across ...
0 votes
1 answer
168 views

Does this inductance measuring oscillator circuit work?

I'm planning to create a circuit to measure inductance by creating a stable sinusoidal oscillator out of it with a known value capacitor. Then measuring the oscillator frequency accurately with an ...
6 votes
4 answers
749 views

Using 50 Ω coax cable instead of passive probe

Preface, why am I asking this question? Instead of using a passive probe with a ground clip, I want a more "permanent" and reliable connection for my measurements. Note: I'm not talking ...
6 votes
3 answers
6k views

Oscilloscope: when to use coaxial instead of probes?

I understand the difference between passive and active probes, and between x1, x10, x100, ... I also understand that at high frequencies the capacitance of the oscilloscope has to be considered, so a ...
0 votes
2 answers
165 views

Which equipment is required to test the no radio device for compliance with electromagnetic compatibility (EMC)?

I am designing a device that has no intention to transmit or receive any radio waves but it has CPU, large PWM driven LED indicators so may be some higher frequencies inside. To make sure we pass the ...
0 votes
3 answers
105 views

How to measure multiple resistances with Arduino Uno, without one measurement influencing the other?

I'm working on a project where I aim to measure resistances using an Arduino Uno. I started with two separate voltage dividers, each using a 1 MOhm reference resistor, connected to a common Arduino ...
0 votes
2 answers
65 views

What is the real resolution of my voltage measurement when I use only some of the range of of the ADCchannel

I have a 16 bit ADC, I use the +/1 V range, differential channel. If I used the full range of the ADC to provide full resolution (I am aware non-linearity and noise may affect this) this calculates as:...
1 vote
2 answers
196 views

Measurement of output current of a photodiode

I am a German student. My task is to conduct a characterization of a photodiode (KPEIMC-UDCOM by Kyosemi.) The photodiode will be illuminated by 850-1550 nm laser diodes. It would be good (but not ...
1 vote
4 answers
2k views

How to calculate measurement error in a voltage divider?

I'm trying to calculate the measurement uncertainty of the voltage represented by the ADC in +/- V or % of a voltage measured across R2 of a voltage divider. What would be the general way to tackle ...
3 votes
2 answers
104 views

My isolation transformer has its protective earth connected to the output neutral. How should I rewire it for my home lab for "DUT probing"?

I have a rather sturdy isolation transformer in my home lab and I just realized that the primary side earth is not only connected to the output side earth but also to the output side neutral. I don't ...

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