US4032782A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature stable multipole mass filter and method therefor
Assignee: Thermo Finnigan LLC
•
Filing: 1976-06-04
•
Granted: 1977-06-28
•
Expires: 1996-06-04
Abstract
Abstract A method of selecting a material for the construction of a multipole mass filter that is temperature stable or in other words, the R o parameter remains invariant with change in temperature. The coefficients of thermal expansion of the quadrupole rods and mounting structure are chosen so that a constant ratio of the two is provided which in turn is determined by the geometrical construction of the filter.
Inventors
- 👤 Ronald D. Smith
- 👤 William J. Fies
- 👤 John R. Reeher
- 👤 Michael S. Story
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:14
CPC Classifications
H; H01; H01J; H01J49/00; H01J49/26; H01J49/34; H01J49/42; H01J49/4205; H01J49/421; H01J49/4215; H01J49/4255
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
83 words
A method of maintaining R o constant over a wide temperature range in a multipole mass filter having rods and a rod mounting means comprising the following steps: determining the theoretical ratio of thermal coefficients of expansion of said rods and said rod mounting means to maintain R o constant with reference to a specific mass filter construction; selecting rods and rod mounting means respectively having thermal coefficient of expansion substantially matching said theoretical ratio; and affixing said rods to said mounting means.
Claim 2
Independent Claim
83 words
A method of maintaining R o constant over a wide temperature range in a multipole mass filter having rods and a rod mounting means comprising the following steps: determining the theoretical ratio of thermal coefficients of expansion of said rods and said rod mounting means to maintain R o constant with reference to a specific mass filter construction; selecting rods and rod mounting means respectively having thermal coefficient of expansion substantially matching said theoretical ratio; and affixing said rods to said mounting means.
Claim 3
Dependent Claim
24 words
A method as in claim 1 where said mass filter is of the quadrupole type with cylindrical rods and said ratio is substantially 1.436.
Claim 4
Dependent Claim
51 words
In a multipole mass filter having rods and mounting means said rods having a first coefficient of thermal expansion and said rod mounting means a second coefficient of thermal expansion said two coefficients being chosen so that the mass to charge ratio passed by said filter does not change with temperature.
Claim 5
Dependent Claim
51 words
In a multipole mass filter having rods and mounting means said rods having a first coefficient of thermal expansion and said rod mounting means a second coefficient of thermal expansion said two coefficients being chosen so that the mass to charge ratio passed by said filter does not change with temperature.
Claim 6
Dependent Claim
22 words
A filter as in claim 3 where the parameter R o of said filter is maintained constant by said choice of coefficients.
Claim 7
Dependent Claim
28 words
A filter as in claim 3 which is of the quadrupole type with cylindrical rods and the ratio of said first to said second coefficients is substantially 1.436.
References Cited (Backward Citations)
US3553451A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-06-27 | 1980-12-27 | 1981-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-27 | 1984-12-27 | 1985-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-27 | 1988-12-27 | 1989-06-28 | $7700.00 | Window Closed / Lapsed |