Tricking the BESS Tester (without meaning to)

[subwoofer]

And this is where it becomes impossible, setting a tension of 100g. There is no way this can be done with an ATF. Even if you could set that and then not change it when securing the clamp, as soon as an edge is brought down onto it everything changes.

My guestimate was perhaps badly expressed. I take up the slack in the filament without tugging hard, and then tighten the clamp nut. One done I gently poke and pluck the filament to get a sense that it is not actually slack, but also not tight. A bit vague but certainly works better than de-tensioning the clips.

My feeling was that as the filament can move a little that small slicing movements (very small) from hand holding should be absorbed, but large slicing motions would totally blow the measurement.

Still considering false readings, I find that when placing the ATF into its cut out, it is possible for it to get caught up on the metal plate. I actually test for this by pressing down hard on a fulcrum sitting on the plate and check for the reading staying at 0. If it registers anything, the ATF is touching the metal plate. If you didn't check this I can imagine a reading being very badly off if the ATF catches the plate.