Patent ID: 7795876

Claim:
A cold cathode pressure sensor comprising: a gastight housing having a test gas inlet; an anode and a cathode arranged in said housing; a radiation source directed to said cathode for igniting a cold cathode discharge; a measuring device for measuring an electric current between said anode and said cathode; and a control device for generating an electrical voltage U AK between said anode and said cathode and for controlling said radiation source, wherein said housing is at least partly made of glass, wherein said radiation source is arranged outside said housing, said radiation source irradiates said cathode through said glass, and said radiation source substantially emits a radiation of a wavelength λof more than 400 nm and less than 1,400 nm, and wherein a radius of curvature r 0 of an edge located closest to said anode of said cathode, and said electrical voltage U AK between said anode and said cathode are selected such that a field strength E in the region of said edge of said cathode is larger than 10 kV/cm and smaller than 1GV/cm.