Keithley 2450 non-equidistant samples

Hello,<br> <br> I obtained a weird behaviour when measuring the inrush current of a device. I adjusted the SMU's samplerate to 2500 samples/sec, but between 20 and 90 ms there were only 3 samples captured (see attached).<br> <br> Does anyone have an explanation or fix to that behaviour?<br> <br> Thank you in advance!<br> Kind regards

System configuration, see attached.

Hello Paul,&#160;<br> <br> I tested your script and could not see any datapoint skipping time. However, I noticed that you are on firmware version 1.6.7c and I tested the script on 1.7.12. Please upgrade to the latest firmware version and let me know if you still have timing issues.&#160;<br> <br> Review the release notes for installation guide:&#160;<a href="https://www.tek.com/en/support/software/firmware/model-2450-firmware-revision-1712-and-release-notes">Model 2450 Firmware Revision 1.7.12 and Release Notes | Tektronix</a>

I forgot to add something. In your test you are using Autorange (smu.measure.autorange = smu.ON). I recommend using a fixed range.&#160;<br> <br> Based on your graph, it seems that you cross the 100mA range and that's when your timing changes. Autorange will affect timing because the instrument has to &quot;figure out&quot; which range is best so it will take some time to adjust and then measure.&#160;<br> <br> In general, adjust your fixed range to the highest expected value so you don't cross it and get overflow.&#160;<br> <br> You can also use&#160;smu.measure.autorangehigh and&#160;smu.measure.autorangelow to restrict the possible ranges the instrument will check when using autorange. This will improve timing but it's not better than using a fixed range.&#160;

The autorange adjustment solved the timing issues.<br> Thank you very much!<br> &#160;