Has anyone done this before?
We have recently run into issues where PRT's begin to drift as the chamber pumps down. This drift can cause up to a 7-12 degree disparity when compared to PRT's outside the vacuum chamber.
Anyone ever figure out the underlying cause?
Recently I placed 2 PRT's in a bell jar. One of them was fully immersed, lead wires and all. The second, only the sensing rod was exposed. After pumping to approx. 100 microns, the PRT's drifted to about 12 degrees apart.
However, I tried placing 12 PRT's within another chamber and had 2 PRT's with the sensing rod exposed.
This chamber pumps to about 10-6 Torr and I have yet to catch any error.
What's happening?