Digital force gauge query

Leverage. As the arm is raised the weight shifts toward the counterweight slightly.

1. The entire mass of a tonearm/cartridge is supported at two points, the bearing and the stylus.

2. Downforce (aka, VTF) is an measure of how much force gravity is exerting on the *portion* of the tonearm/cartridge mass that's being supported by the stylus. (The remainder of the tonearm/cartridge mass is still being supported by the bearing.)

3. When you raise/lower your scale (or arm base, as with VTA adjustment) it changes the angle of the arm. This shifts a small percentage of the armtube and it's mass from one side of the bearing support point to the other.

4. More mass on the scale side of the bearing = more weight being supported by the stylus = higher VTF. Less mass on the scale side of the bearing = less weight being supported by the stylus = lower VTF.

I measured my Mystic Mat against the platform of the gauge with a ruler and found them to be essentially the same height. So, to my way of thinking, these eseentially cancel each other out, i.e. placing the gauge directly on the platter is the equivalent of where the stylus would otherwise meet the mat. In order to allow for the height of a record, I removed the mat, placed an average weight record directly on the platter and placed the gauge on the record, measuring for the optimum VTF for my cartridge, which is 1.8g. Seems a logical solution.

Just imagine an arm at a 45 degree angle (a very thick mat!) and you can easily see how the measurement would be lower.

"Just imagine an arm at a 45 degree angle (a very thick mat!) and you can easily see how the measurement would be lower"
-------------------------------------------
Your example would cause an increase in VTF, not a lower value.