US4383431A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Auto-zero system for pressure transducers
Assignee: Lam Research Corp
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Filing: 1980-11-03
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Granted: 1983-05-17
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Expires: 2000-11-03
Abstract
Abstract An apparatus for automatically compensating for deviation of a capacitance manometer reading from true pressure. The capacitance manometer is connected to a source of pressure having a value less than the pressure the capacitance manometer is capable of reading and the indicated pressure is stored as a correction factor. Thereafter, each pressure read by the manometer is adjusted by the correction factor.
Inventors
- 👤 Barry Gelernt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:31
CPC Classifications
G; G01; G01L; G01L27/00; G01L27/002; G01L27/005
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
98 words
An apparatus for correcting zero drift of a capacitance manometer, comprising in combination; pump means, first means connecting the capacitance manometer to said pump means when said pump means is at a pressure at least an order of magnitude less than the lowest readable pressure of the capacitance manometer, second means connected to the capacitance manometer recording the reading of the capacitance manometer as a correction factor when it is connected to said pump means, third means connected to the capacitance manometer and said second means for applying said correction factor to subsequent readings of the capacitance manometer.
Claim 2
Independent Claim
98 words
An apparatus for correcting zero drift of a capacitance manometer, comprising in combination; pump means, first means connecting the capacitance manometer to said pump means when said pump means is at a pressure at least an order of magnitude less than the lowest readable pressure of the capacitance manometer, second means connected to the capacitance manometer recording the reading of the capacitance manometer as a correction factor when it is connected to said pump means, third means connected to the capacitance manometer and said second means for applying said correction factor to subsequent readings of the capacitance manometer.
Claim 3
Dependent Claim
14 words
An apparatus according to claim 1 wherein, said pump means is a diffusion pump.
Claim 4
Dependent Claim
14 words
An apparatus according to claim 1 wherein, said pump means is an ion pump.
Claim 5
Dependent Claim
14 words
An apparatus according to claim 1 wherein, said pump means is a turbomolecular pump.
Claim 6
Dependent Claim
13 words
An apparatus according to claim 1 wherein, said pump is a sorption pump.
Claim 7
Dependent Claim
31 words
An apparatus according to claim 2 further including, mechanical pump means connected to said diffusion pump to pump said diffusion pump to a pressure at which said diffusion pump operates efficiently.
Claim 8
Dependent Claim
31 words
An apparatus according to claim 3 further including, mechanical pump means connected to said ion pump to pump said ion pump to a pressure at which said ion pump operates efficiently.
Claim 9
Dependent Claim
32 words
An apparatus according to claim 6 or 7 further including, sensor means connected to said pump means for determining that said pump means is operative prior to connecting the capacitance manometer thereto.
Claim 10
Dependent Claim
42 words
An apparatus according to claim 8 further including, a process module containing a chamber whose pressure is to be monitored by the capacitance manometer, said first means connecting the capacitance manometer to said process module after said correction factor has been recorded.
Claim 11
Dependent Claim
25 words
An apparatus according to claim 9 further including, display means connected to said third means for displaying the corrected pressure read by the capacitance manometer.
Claim 12
Dependent Claim
22 words
An apparatus according to claim 10 further including, permanent storage means connected to the capacitance manometer for recording each correction factor thereof.
Claim 13
Dependent Claim
61 words
An apparatus according to claim 11 further including, control means connected to said first means, computer means connected to said control means, said computer means including said third means and receiving an input from said sensor means for causing said first means to connect the capacitance manometer to said pump means when said sensor means determines said pump means is operative.
References Cited (Backward Citations)
US4204422A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-05-16 | 1986-11-15 | 1987-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-16 | 1990-11-15 | 1991-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-16 | 1994-11-15 | 1995-05-17 | $7700.00 | Window Closed / Lapsed |