My advice is always to “record the data you are going to want to process
later”.
In most cases, this means “record a data point every timestamp, so that later
you can display what the value at that timestamp was”.
There are dozens (at least) of questions on this list and the Grafana list of
people doing things like measuring when water gets added to a tank, or removed
from it, and then later they want to display the level (quantity) of water in
the tank over some period of time.
This is far from simple to do, because they did not record the quantity of
water in the tank - they recorded when this changed, but that’s not what they
want to display afterwards.
So, in summary, think about what it is you want to see on your instrumentation
system at the end of the whole measurement / analysis process, and make sure
you are recording the data that’s needed to show that.
Antony.
