Invention Grant
- Patent Title: Cold cathode ionization vacuum gauge with multiple cathodes
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Application No.: US15499064Application Date: 2017-04-27
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Publication No.: US10337940B2Publication Date: 2019-07-02
- Inventor: Timothy C. Swinney , Clinton L. Percy , Duane W. Marion , Brandon J. Kelly
- Applicant: MKS Instruments, Inc.
- Applicant Address: US MA Andover
- Assignee: MKS Instruments, Inc.
- Current Assignee: MKS Instruments, Inc.
- Current Assignee Address: US MA Andover
- Agency: Hamilton, Brook, Smith & Reynolds, P.C.
- Main IPC: G01L21/34
- IPC: G01L21/34 ; H01J41/06 ; G01L21/32 ; G01L21/30

Abstract:
A cold cathode ionization gauge includes multiple cathodes providing different spacings between the cathodes and an anode. The multiple cathodes allow for pressure measurements over wider ranges of pressure. A first cathode with a larger spacing may provide current based on Townsend discharge; whereas, a second cathode having a smaller spacing may provide current based on both Townsend discharge at higher pressures and on Paschen's Law discharge at still higher pressures. A feature on the second cathode may support Paschen's Law discharge. Large resistances between the cathodes and a return to power supply enable control of output profiles to extend the pressure ranges with accurate responses and avoid output minima. Pressure measurements may be made based on currents from respective cathodes dependent on the outputs of the cathodes through the wide pressure range of measurement. The multiple cathodes may also provide measurements that avoid the discontinuities found in current outputs of the respective cathodes.
Public/Granted literature
- US20170315012A1 COLD CATHODE IONIZATION VACUUM GAUGE WITH MULTIPLE CATHODES Public/Granted day:2017-11-02
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