PC‐based spinning rotor gage controller

The spinning rotor gage (SRG) is a molecular drag vacuum gage. Commercial versions are available that operate between about 10−4 and 1 Pa. In this paper we describe the design, and present performance data for a new SRG controller that uses a plug‐in peripheral board and a personal computer (PC) to perform all control, signal processing, and data analysis functions. This controller offers several advantages over those presently available, including the simultaneous operation of multiple SRGs (at least four SRGs with a single PC), complete software control of all operating parameters, and significantly improved low‐pressure performance.