I prefer just using gauges on about 20% of the laterals at the top and a handful on the same lines at about 15-18' elevation above the main line saddle. To know how the rest are doing, just compare the flow with a line of simplar slope and # of taps that has a gauge. It is easy to compare on 3/16 where on 5/16 you can not easily compare visually.
Use the cheap gauges and get a few extra. If one fails, change it out. Those gauges ARE cheap and do fail and are not very accurate, but they still give a good idea of what is happening.
Dave Klish, I recently ordered a 2x6 wood fired evaporator from A&A Sheet Metal which I will be converting to oil fired
Now have solar, 2x6 finish pan, 5 bank 7x7 filter press, large water jacketed bottler, and tankless water heater.
Recently bought another Gingerich RO, this one was a 125, but a second membrane was added thus is a 250, like I had.
After running a 2x3, a 2x6, 3x8 tapping from 79 taps up to 1320 all woodfired, now I'm going to a 2x6 oil fired and a 200-425 taps.