Abstract: The method includes the steps of assembling one or more blanks (1) in supporting means (2, 3) so that the or each blank occupies at least the space to be occupied by elongate electrodes and, without disturbing the position of the blanks relative to said supporting means, removing material from all said blanks to generate said electrodes in position in said supporting means. Preferably the material is removed by an electrode-discharge machining (EDM) process, e.g. diesinking. The method avoids time-consuming alignment of preformed electrodes in said supporting means.

Abstract: The invention provides a wide range pressure gauge comprising a thermal-conductivity gauge and a high-vacuum total or partial pressure gauge such as a hot-cathode ionization gauge or a residual gas mass spectrometer, mounted from a common flange. In order to allow the use of a filament (3) shorter than those conventionally used in thermal conductivity pressure gauges, means (49-54) are provided to maintain the filament temperature substantially constant over its entire pressure range. Pressure is measured by means (51, 52, 56-58) adapted to measure the power dissipated in the filament (3).