Abstract
A torsion balance of the suspended beam type has been set up by welding fused quartz rods and fibers. It can be loaded up to 20g and is sensitive to a valueless than 0.1μg.
Equilibrating the change of weight with the torsion of the quartz fiber, a change in mass up to 200μg can be measuredusing a smallangle measuring device utilizing moiré fringe as the null detector.
The stability of the rest point of the beam is less than ±0.15μg, andthe standard deviation of the reproducibility of the beamdeflection when a tinyweight is loaded and unloaded is 0.3μg. The linearity of the torsion fiber is of the order of a μg.
