Electricity: measuring and testing – Using ionization effects – For monitoring pressure
Reexamination Certificate
2006-07-18
2008-09-30
Nguyen, Vincent Q. (Department: 2831)
Electricity: measuring and testing
Using ionization effects
For monitoring pressure
C324S459000, C315S095000, C315S108000
Reexamination Certificate
active
07429863
ABSTRACT:
A method and apparatus for operating a multi-hot-cathode ionization gauge is provided to increase the operational lifetime of the ionization gauge in gaseous process environments. In example embodiments, the life of a spare cathode is extended by heating the spare cathode to a temperature that is insufficient to emit electrons but that is sufficient to decrease the amount of material that deposits on its surface or is optimized to decrease the chemical interaction between a process gas and a material of the at least one spare cathode. The spare cathode may be constantly or periodically heated. In other embodiments, after a process pressure passes a given pressure threshold, plural cathodes may be heated to a non-emitting temperature, plural cathodes may be heated to a lower emitting temperature, or an emitting cathode may be heated to a temperature that decreases the electron emission current.
REFERENCES:
patent: 3153744 (1964-10-01), Torney, Jr.
patent: 3591827 (1971-07-01), Hall
patent: 4018489 (1977-04-01), Miller et al.
patent: 4412153 (1983-10-01), Kalbfus et al.
patent: 5256947 (1993-10-01), Toy et al.
patent: 5438238 (1995-08-01), Toy et al.
patent: 6054862 (2000-04-01), Zhou
patent: 6525482 (2003-02-01), Miyamoto
patent: 6566884 (2003-05-01), Rutherford et al.
patent: 7030619 (2006-04-01), Arnold et al.
patent: 2005/0140375 (2005-06-01), Liu
patent: 2006/0012373 (2006-01-01), Edelmann et al.
patent: 57019949 (1982-02-01), None
patent: WO 2005/045877 (2005-05-01), None
Arnold Paul C.
Blouch Stephen C.
Borenstein Michael D.
Carmichael Larry K.
Knott Richard A.
Brooks Automation Inc.
Hamilton Brook Smith & Reynolds P.C.
Nguyen Vincent Q.
Zhu John
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