ABSTRACT: For many years standard vacuum pressure measurement sensors consist of capacitance diaphragm gauges, Pirani heat transfer gauges as well as ionization gauges. Development has progressed from passive gauges with a detached controller to combination gauges with integrated electronics. Market demand from industry continues to force the development of smaller, cheaper and better process sensors. Better in this context means the sensors must survive the harsh industrial process conditions for longer, measure faster and with better reproducibility. In the area of vacuum pressure metrology new developments are occurring in national measurement institutes and universities. The pressure is determined by measuring the refractive index. I will present some of the recent developments.