Bell jar test facility #2 is set up similar to the first bell jar. It is a 0.5 m diameter by 0.7 m tall stainless-steel bell jar vacuum system, evacuated by a CVC PMC-4B diffusion pump which is backed mechanically by an Adixen 2021 SD rotary vane pump. The diffusion and backing pumps have pumping rates of 700 l/s (on air) and 6.9 l/s, respectively. Oil is prevented from entering the chamber by an uncooled optical baffle. Chamber pressure at high vacuum is monitored using a Bayard Alpert 571 ion gauge which is connected to a SenTorr ion gauge controller.