According to the SE Master Programming manual, the 3/4" turbine meter does indeed give you 126 pulses per gallon. The 1" paddle wheel meter like mine gives you eight pulses per gallon. There's also a 3/4" paddle wheel meter that gives you 20 pulses/gal.
You can buy the complete 3/4" paddle wheel flow meter assembly for about $125. I wonder if it would work if you plumbed one of these things "standalone, in-line" downstream from the softener and just used it as a flow meter? You could buy a 24V wall wart to power it. What else could you use with it to count the pulses?
For anyone who is interested,
this manual shows the electronics diagram for the controller on page 48. Page 34 shows the various meter assemblies. In "figure 31" at the top of page 34, the 3/4" paddle wheel flow meter is shown at the top left of the page as "item 1". "Item 3" at the top right of the page is the 3/4" turbine wheel flow meter. The 1" paddle wheel flow meter shown as "figure 32" is what mine has. The 1-1/2" meter shown in figure 33 sells for about $700. It's all brass, while the others are made of a plastic called "Noryl" (at least mine is).
So...either 126, 20, or 8 pulses/gal depending on the meter seems like pretty good granularity since the "regular" water meters are one pulse/gal. I checked earlier today, and mine picks up a pretty small trickle.
If someone can explain to me what it will take to integrate one of these (not the one in the softener) into my Elk-M1G/Barionet/CQC/whatever environment, I will probably give it a shot.
Thanks,
Ira