Hi and thank you for your post.
This depends on the scope that you are using. To measure a 1KHz sine wave we recommend at least 5 times the sampling interval, ,depending on how good of a representation you may want 10 or 20 times that sampling interval.
In PicoScope 5 there are 2 modes of operation Block Mode (quicker than 200ms per div) and Streaming Mode (slower than 100ms per div). You can change the scope to be on block mode on 200ms and slower. To do this you need to go to
Settings->Options->Advanced->Slow Sampling (>100ms/div) Block mode
Also increase the "Maximum samples per scope trace" to 1000000. When you run it on say 5 seconds per div, it will take 50 seconds to capture the data onto the memory of the scope and then transfer it to the PC. You can then pause the capture and choose The zooming option next to the time base and scroll through the results.
In terms of fast streaming this mode is only available for the 3224/3 and 3424/3 using PicoScope 6 or if you want to write your own software.
Hope this helps.