RE: Rns monday10 May 2019 17:24
I was once told that the engineers interpret the results on a log-based graph - so 1 second, 1 minute, 1 hour, 1 day.... instead of 1,2,3 etc along the bottom (the maths are probably mind-boggling...)
This means they need very long flow periods to see what they really want - a short build-up gives useful pressure data but the longer the test the better I was told. Plus of course the longer they're doing nothing the closer they get to the natural, undisturbed values instead of trying to look at pressures while the pump is going up and down...... bit like ripples in a lake I guess.......
A long build-up suggests a careful, scientific approach to get the data needed for a CPR - this way the range of values computed will be much tighter than say a 12 hour build-up. They must be feeling quite confident