Hot cathode ionization gauge calibration with the KRISS ultra-high vacuum standards

Abstract

The calibration system for ultra-high vacuum standards at the Korea Research Institute of Standards and Science (KRISS) uses a restriction in the range 5 10 -7 Pa to 2 10 -3 Pa. Using this system, we have calibrated for argon two commercially available gauges, an extractor gauge and a stabil-ion gauge. The correction factor of the extractor gauge in the lower pressure range was about 1.07 but it rose by 4 %, reaching 1.11 at 2 10 -5 Pa, while that of the stabil-ion gauge slowly decreased from 1.04 to 1.02 over four decades of the pressure range. K

Generation of extremely high vacuum by ordinary procedures with a SUS304 vacuum chamber and total and partial pressure measurements by hot cathode ionization gauges and a quadrupole mass spectrometer

“…The more serious ESD ion current is mainly caused by electrons colliding against the anode of the gauge, and it is determined by the size and material of the anode and the size of the hot electron current occurring at the filament [5]. The Leybold company developed an Extractor gauge for measuring XHV, which is equipped with a reflector to block the ESD current, for the first time in the world [6]. Recently Akimichi et al succeeded in lowering the measurement range down to 10 −10 Pa, which isolates gas phase ions and ESD ions and then removes ESD ions with an energy filter [7][8][9].…”

“…In addition, with regard to its experiment on the temperature characteristics of three ion gauges at high vacuum and temperature between 20 • C and 26 • C, KRISS Vacuum Center reported that the difference from the indicated pressure varied from 5.0% to 10.3%, reacting sensitively to any change in ambient temperature [18]. According to the results of ion gauge calibration at standard pressure 7.3678 × 10 −7 Pa by the KRISS ultrahigh vacuum standard system, the uncertainty due to the temperature change was 1.253 × 10 −10 Pa, which was 0.67% of the total combined standard uncertainty 1.852 × 10 −8 [19]. Such a temperature effect arises not only from the gauge sensor but also from the outgassing of the equipment.…”

“…KRISS Vacuum Center evaluated the uncertainty of IG A and IG C according to ISO guidelines in the pressure ranges from 7.3678 × 10 −7 Pa to 1.8941 × 10 −7 Pa, and reported that the two gauges differed in pressure ratio (indicated pressure/standard pressure) by a maximum of 7% [19]. In addition, the results were verified by the Committee Consultatif pour la Masses et les grandeurs apparentees (CCM) key comparison [20] Figure 7 shows pressure readings of IG A , IG B and IB C versus number of measurements.…”

Final report on the key comparison, CCM.P-K15 in the pressure range from 1.0 × 10-4 Pa to 1.0 Pa

“…The primary standard for ultra-high vacuum (UHV) at KRISS used for this comparison is an orifice type dynamic expansion system as described in [1]. It consists of two dynamic calibration systems: one for high vacuum from 10 −5 to 10 −2 Pa, and the second for UHV from 10 −7 to 10 −5 Pa.…”

Investigation of gas species in a stainless steel ultrahigh vacuum chamber with hot cathode ionization gauges

“…The ultrahigh vacuum system for this study is basically a twostage flow-divider system. It is similar to the commonly used orifice flow-type vacuum gauge calibration system [15]. The system consists of a main chamber, a pumping unit, two hot cathode ionization gauges, an RGA and a baking arrangement.…”