Contrast ratio

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jcclq
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Contrast ratio

Post by jcclq »

Hi

I would like to create a mathematical function from 2 measurements. I managed to display the minimum (Min) and maximum (Max) of the waveform, but now I would like to display in real time the contrast ratio: (Max - Min)/(Max + Min).

I could not find in the manual how to do it, but is it possible?

Thanks a lot!

JC

Gerry
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Re: Contrast ratio

Post by Gerry »

Hi jcclq,

Are you referring to the Measurements at the bottom of the display?

Regards,

Gerry
Gerry
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sbabic44
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Re: Contrast ratio

Post by sbabic44 »

Like this ?

(max(A)-min(A))/(max(A)+min(A))

you paste that in math line..

It will give you math waveform with that function...

jcclq
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Re: Contrast ratio

Post by jcclq »

Ok thanks Gerry, I'll try that.

Best regards
JCC

jcclq
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Re: Contrast ratio

Post by jcclq »

Hi

I created a new line in the math channel, but then I am not sure what to do. It does not seem to plot the formula (max(A)-min(A))/(max(A)+min(A)). I don't see anything in the bottom lines ('Measurements').

To refine my question: My signal is an oscillation of varying amplitude and DC level, which varies the value of min(A) and max(A), so also (max(A)-min(A))/(max(A)+min(A)). I would like to visualize this on the screen, either as a plotted signal vs time, or a value I could read.

Thanks
JC
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Gerry
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Re: Contrast ratio

Post by Gerry »

Hi jcclq,

Sorry I have been tied up doing other things.

After entering a Math formula, you need to
(a) set the Range and units correctly. If it is way too large the Math Channel will appear as a flat line, if it is way too small it won't appear at all (it will be out of range).
(b) Turn the Math channel on by ticking the check box for the newly created Math channel once you exit the editing windows.

If that still doesn't reveal the waveform, then the problem will be with the waveform (e.g. where it has been constant for a while there will be a value of zero, and where it crosses the zero line you will get -ve and -ve infinity either side of the zero point).

Regards,

Gerry
Gerry
Technical Specialist

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