Host: The Japan Society of Vacuum and Surface Science
A capacitance manometer using sapphire has been developed for semiconductor manufacturing processes. Taking advantage of features such as high precision and good long-term stability, its use has been adopted for vacuum freeze-drying devices. However, zero point shifts were discovered after Cleaning in Place (CIP) and subsequent Sterilization in Place (SIP) processes. In order to resolve this problem, temperature measurements and thermal fluid simulations were performed with various conditions to estimate the source of the shift. Following this analysis, a capacitance manometer able to withstand the vacuum freeze-drying process has been developed.
