Cylindrical hot cathode ionisation gauge – Construction and testing

Hot cathode ionisation gauges are indispensable in measuring high and ultra-high vacuum. In the present work the construction details and the metrological evaluation of a novel gauge design — the cylindrical ionisation gauge is presented. With the aim of enhancing accuracy and stability both in the short and long term, details of the mechanical assembling of electrodes and precautions to minimize leakage currents influencing ion current measurement are described. Performance evaluations demonstrate high short-term stability, with linearity error, reproducibility, and repeatability values consistently below 1 %, placing the gauge at the same level as the most stable ionisation gauges. Operating across a pressure range of at least 6 orders of magnitude, the gauge exhibits low linearity error from high to ultra-high vacuum ranges. Its capability to measure pressures below 10−9 mbar remains open and requires further investigation.