While the MCPC logs to its SD card at a consistent 1 Hz cadence, the raspberry pi log contains a missing data point every few seconds (more specific analysis here. There are a few potential fixes here, issue 2 has some relevant commentary and we can also see what's up from our friends at Brechtel. We should finish analyzing the data from when we discovered this to look for any patterns, and then go ahead and see if there are ways we can change how we read the data to be more consistent.