Dielectric Test Cavity for 3D Printing Filament

I created a resonant cavity used to test the dielectric constant and loss tangent of filament used for 3D printing. We are 3D printing microwave lenses, and need to know these properties. This is a WR-90 TE101 cavity with a hole in the center where filament can be inserted. Perturbation theory tells you how the resonant frequency and Q will change when dielectric is added to the cavity.

The formulae can be found on Wikipedia

https://en.wikipedia.org/wiki/Cavity_perturbation_theory

Exper