Real time gas usage

I wondering how the graphic on the website could be possible when you use little gas (heating water for ex.) because then, there is only one pulse (mine is 1 pulse/10 liter) and i think there can't be any calculation done to it.
Is the real time gas usage then ignored or is it stored in the FLM's memory ?
I like to know how the pulse and analogue calculations are done in the FLM's program.
Is there a file on Github where i can read that ?