how to measure pulse height by DAQ card

[hanh]

I want to record pulse signals (fast pulse) and measure their amplitude (height) using DAQ card

[S.Klumpp]

Hi hanh,

you could use the "Amplitude and Levels".VI from the Analyse Menu. But for my opinion it is rather slow.
How is the shape of your pulses and what is fast for you ?

Regards ...

Stephan

[hanh]

thanks alot
I work with photomultipier tube, their output pulses are fast (20-50 microsecond)(monopopar -). I am willing to make a simple multichannel analyser in radiation measurements

[S.Klumpp]

🙂 I heard that problem before. Is it possible that we disscused this subject some time earlier?
Well, but to your problem. How many counts do you get per second in average? I work/worked at a similar problem to analyse the counts from a 2D-detector. I tried the VI mentioned above but it was never able to analyse 1000 counts per second as a order of magnitude.
Which shape has your pulses? Are they NIM or square shaped? How stable is your underground and of which order of magnitude is it? How fast is your DAQ board? Because according to the Nyquist theorem you will need a sampling rate of approx. 1MS/s to resolve them properly!

Stephan

[hanh]

In my case, the count rate is very low ( about several pulse/sec), the amplitude is about 20-50mV. The pulse shape is needle shape, I mean it rising edge is about 1-10micro sec, the falling one is about 20-50 micro second. I want to count the pulse and its amplitude as the same time. Thanks

[S.Klumpp]

Well, with these conditions I would try the VI which I mentioned above and estimate the dead time of your analysis software wheather it gets all counts produced by the multiplier. As sampling rate I would choose something between 200kS/s and 500kS/s per channel.

Regards ...

Stephan