Am I correct in assuming that aperture time does not actually equal measurement time? I'm asking because I cannot measure the peak value of a 10us pulse even with with an aperture of 500ns. DSDC mode works fine, but I lose the auto ranging which is a nice feature of DCV mode. I've exhausted all of the options in the manual regarding digitizing with DCV mode, but can't seem to find a way to measure a peak value on anythign less than a 25us long pulse. And even then I have to delay the measurement 20us into the pulse to get a correct reading. It almost seems as if there is a ~40kHz low pass on my signal. If anyone has any ideas I would love to hear them.
Thanks!
Thanks!
How do you currently have the 3458A setup, maybe you could provide a command list?
You are correct that aperture does not equal total time per measurement. There is a lot of things that play into that ex: autozero, autorange, config time, bus time (if programming), etc....
The aperture is how long the actual signal is measured, but that is just one part of the process.
Now the max readspeed in DCV mode is 100Ksamples/sec, and the settings need to be just right to achieve that speed, and your signal is 100KHz, that's only 1 sample per cycle. The chances of you getting the peak is not very good. Normally I suggest digitizing a signal then just turning on math and looking at the max min, or post process the data yourself, but if your signal is 100KHz, that's not going to work. In order to fulfill nyquist your signal would have to be 50KHz or less, and that's pushing it.
One other note, you are correct DSDC mode is better at capturing peaks than DCV. You say you like DCV because of autoranging but, in DCV, if your autoranging there is no way your gonna sample quickly enough to capture the pulse you want. You must use a manual range.
I'll be happy to help best I can if you provide some more information, but I'm not promising you'll be able to do what you want in DCV mode.