I have been using a Picoscope 4000 series with Picoscope 6 software for measuring data from High rate tensile material tests. I have used if successfully for several months and been getting good data.
Recently, I ran some tests at 100 in/s stroke rate and for some reason in the data I read from the picoscope the x-axis data shows scaled by 2. It shows double the time. I know this because I have 3 strain gages on my specimen and two of them are being recorded by the test machine and the third one is recorded by the picoscope. I have successfully tested at 1 in/s, 20 in/s and 50 in/s stroke rate but for 100 in/s I see this problem.
For each of the above stroke rates, I have changed the divisions and sampling rate. For 100in/s I was using 10 MS/s and 100,005 samples. The window division was 1 ms/div. I am using a single trigger with slope and trigger was set to 40 mV.
From the test machine, I deduced that the machine overshot and instead of loading at 100 in/s it was loading at 200 in/s and the specimen extends 0.2 in to failure. That tells me that my strain measurements should last 0.001 seconds which is what I get from the Test Machine. But the PicoScope data shows strain range 0.002 seconds.
Please help with this problem.