I don't have any training but am doing some hobby electronics. I would like to record a change in voltage over time, sampled at around 100+ kHz. Ideally, I'd like to record around 20-30 min of two different channels, so I guess that works out to be at least 240 million samples. I'd like to view this recording on my Windows computer similar to a stereo .wav PCM waveform. (In fact, if I could save it as a .wav file, that'd be ideal.)
I considered simply using a sound card to make this recording, but this seems to not be possible with a DC signal.
Is this something that a digital oscilloscope can do? Or is there a tool designed for this specific task of recording to a file, similar to the line-in on a sound card? Converting to digital and streaming over USB to record on a PC seems to be what I'm ideally looking to do.
Edit: Giving some context as requested… This is for a latency test. I am wanting to record a variable latency of a video game system plus an HDMI adapter. Using a photodiode I can create a voltage stream that will show when the result appears on screen and compare it to when a button was pressed. (Hence why two channels are needed.)
Thanks!
Best Answer
This is what bench meters are great for. A number of them can sample well into the 100's of kilosample/second. The problem is that these can be expensive (for a hobby).
Digital oscilloscopes cannot do this. They take snapshots, based on the trigger. Usually, inside, the ADC is constantly writing to a buffer, that has a certain length. When a trigger even occurs, this buffer is then stored and processed. Once that happens, the ADC starts writing to the buffer again and the process starts from the front. As a result, a scope will not be able to measure everything. Some get very close though.
However - some oscilloscopes might be able to capture the entire thing you ask for in their buffer, at low sampling speeds. However, they are not going to be cheap.
I do believe there are modules from National Instruments and others that can do this, but these will be very expensive, and require a PXI chassis, which again is very expensive.
UPDATE: As first pointed out by Marcus Müller, and confirmed by Matt, apparently some Picoscopes do support continuous sampling, which would make them a suited for the application of a 100 kS/s continuous sampling digitized (I am aware that the scope of the question has changed since posting this answer, but I am keeping it here for people in the future who might indeed require continuous sampling)