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# Why are the units of a sampled signal Volts*Hertz?

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#### Processingdata

##### Newbie
Hello,

I'm posting here because I don't understand why when we have a signal, let's say a voltage, why the units of its sampled version are Volts multiplied by Hertz and not just only Volts? It's something I've seen in my course and this is what our teacher taught us but it's doesn't make sense to me.

He also taught us than the unit of the Z-Transform of this sampled signal is in Volts (whereas to me it's would have been more logical to have V.Hz for this one).

It would be nice if you could help me.
Thank you.

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Hello,

I'm posting here because I don't understand why when we have a signal, let's say a voltage, why the units of its sampled version are Volts multiplied by Hertz and not just only Volts? It's something I've seen in my course and this is what our teacher taught us but it's doesn't make sense to me.

He also taught us than the unit of the Z-Transform of this sampled signal is in Volts (whereas to me it's would have been more logical to have V.Hz for this one).

It would be nice if you could help me.
Thank you.
You better follow your teacher and pass your course first. Then when you find a job you can correct such issues.

You better follow your teacher and pass your course first. Then when you find a job you can correct such issues.
I don't understand your reply. I was just asking this because I wanted to understand why it was the case. This question was in one of my exercises.

Hi,

honestly I never heard of unit V * Hz .....
Maybe you should give some context.

Klaus

sampled data on signed n-bits would be just binary values between -2^n-1 & +2^n-1-1 e.g. for 16 bits it will be -32768 to +32767 for full range.
Any volt values at ADC will be mapped to above range. So neither volts, nor volts.Hz make any sense.
But I can relate to volts if I need to. Hz is frequency domain unit and it can related to spectrum but that is not mentioned in your post.

Generally speaking, sampled data is time discrete but not necessarily amplitude discrete. Think e.g. of switched capacitor circuits.

The meaning of V*Hz unit is also not clear to me, I don't remember to have ever seen it in the said context. But may be it's something rather trivial, just need to see a usage example.
--- Updated ---

Generally I would associate V*Hz with a differential operation, H(s) = s.

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The only search result for volt.Hz I found is below (Keysight), nothing to do with sampled data:

The Volt-Hz product is a peak measurement, so for a signal with a maximum high frequency content of 1 KHz and 100 Vpeak, the Volt-Hz product is 10^5 or 100K.

FvM

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