• Journal of the Korean Vacuum Society
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• v.7 no.4
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• pp.277-284
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• 1998

To establish the calibration system of hot cathode ionization gauges as transfer gauges, researches were concentrated on measurements of the pressure ratio, the orifice conductance as well as the porous plug conductance of a ultrahigh vacuum standards system. Two ionization gauges obtained from two different vendors were calibrated in the pressure range of $7{times}10^{-7}$ to $4{times}10^{-3}$ Pa by injecting argon gas into the standards system. As a result, a 4% difference was revealed in non-linearity of the extractor ionization gauge due to the pressure difference between high vacuum and ultrahigh vacuum, and 3% for the stabil ionization gauge. It has been understood that the extractor ionization gauge is able to be used within the 10% error, the uncertainty of the extractor ionization gauge, if properly regulating the sensitivity of the gas. The stabil ionization gauge was also proved to be useable in the maximum error margin of 4% without the control of the gas sensitivity.

• Journal of the Korean Vacuum Society
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• v.12 no.4
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• pp.201-206
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• 2003

A residual gas analyzer was used to study the outgassing behavior of stainless steel 304 chamber as a function of bake-out temperature up to $235 ^{\circ}C$ and to identify the gas species evolved during turn on and degassing of the three different types of hot cathode ionization gauges. It was found that $H_2O$, CO, and $H_2O$ were the dominent outgassing species in the vacuum chamber during bake-out but finally $H_2$ and CO(mass 28) persisted at room temperature. Dominant outgassing species were also $H_2$ and $H_2O$ while fuming on the ionizations and then $H_2$,$H_2O$ and CO were found to be the main species degassed gauges. It was appeared that the outgassing species and quantity were not agreed to the three different types of hot cathode ionization gauges.

• Journal of the Korean Vacuum Society
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• v.13 no.2
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• pp.54-58
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• 2004

Three hot cathode ionization gauges (HCIG) were used to study their responses of pressure measurements at the stainless steel high vacuum (HV) chamber around room temperatures. The pressure variations of HV measured by the three HCIGs between $20 ^{\circ}C$ and $26 ^{\circ}C$ were 5.0 %, 5.3 %, and 10.3 %, respectively. However, pressure differences between $21.5 ^{\circ}C$ and $22.5^{\circ}C$ were lower than the gauges uncertainty limits. The pressure variations of the HCIGs at the HV chamber was not directly affected by gauge characteristics, but pressure changes due to room temperatures.