Saba Tabassum (13221) creator text Islamabad (Unpublished) 2022 monographic xiii, 46 p. : ill., Col. ; 30 cm. +CD Submitted in partial fulfillment of the requirements for the degree of Master of Philosophy in Physics to the Department of Basic Sciences. Includes bibliographical references. Thesis supervisor: Dr. M. Farooq Nasir Thesis Co-supervisor: Dr. Muhammad Maqsood Thesis (M.Phil)--Riphah International University, 2022 English Physics Molecular density Vacuum metrology Ionization gauges Extractor gauges DBS FEAS 530 SAB