With help of Yuhang we removed #3 from the translation stage.

Then, I measured the bulk reference sample at the usual position and got R = 0.611 cm/W.

I installed the 1.5 inch sample and measured its absorption at the longitudinal center.

I measured about 35 ppm/cm which is compatible with old measurements.

Finally, again with Yuhang help, we installed the #4 and started absorption measurement.