Energy Consumption Counter - but not what you think... (OZ counter for bottle prep machine)

Our baby formula prep machine pump appears to draw between 50-100 watts for 7.5 seconds per OZ (30ml).

I already have an automation that lets us know what time the bottle was made. (as it’s surprisingly easy to forget when you are new parents). I thought I could extend it to let us know how many OZ/Ml the bottle was made to… but having sat down to do it, actually can’t figure out how to implement it.

I see that if not careful, I could end up triggering sensors upto and including the actual bottle size. because if I say delay_on for 30s (4OZ), and another sensor delay_on for 37.5s (5OZ) then for a 5OZ bottle, both would trigger.

So then I thought, I just need one sensor that increments per 7.5 seconds that the power consumption is in a certain range… not seen anything like that in the docs, or in my searches so far.

any ideas? Thanks