US4237451A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and means for continuously sampling a fluid
Assignee: Spectrex Corp
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Filing: 1979-02-09
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Granted: 1980-12-02
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Expires: 1999-02-09
Abstract
Abstract An improved air-sampling pump of miniature size ideally suited for carrying on a person includes monitoring circuitry which controls motive pump-energizing signal applied to an air pump to ensure that sampled air is pumped through a test chamber at a substantially constant rate over an extended period of time and also includes alarm circuitry which provides comtemporary and residual indications of interrupted flow rate during the sampling period.
Inventors
- 👤 Keith E. Hollenbeck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:44
CPC Classifications
H; H02; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/285; H02P7/288; G; G01; G01N; G01N1/00; G01N1/02; G01N1/22; G01N1/24
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
104 words
Fluid-sampling apparatus including fluid-pumping means arranged to pump fluid through a test chamber, the apparatus comprising: motor means coupled to the fluid-pumping means for pumping fluid through the test chamber at a flow rate which is determined by the characteristics of applied motor current and fluid pressure differential across the test chamber; monitoring means coupled to the motor means for producing a signal proportional to the motor current therethrough; and circuit means responsive to the signal from said monitoring means for supplying current to said motor means through the monitoring means to maintain the flow rate of fluid through the test chamber substantially constant.
Claim 2
Dependent Claim
104 words
Fluid-sampling apparatus including fluid-pumping means arranged to pump fluid through a test chamber, the apparatus comprising: motor means coupled to the fluid-pumping means for pumping fluid through the test chamber at a flow rate which is determined by the characteristics of applied motor current and fluid pressure differential across the test chamber; monitoring means coupled to the motor means for producing a signal proportional to the motor current therethrough; and circuit means responsive to the signal from said monitoring means for supplying current to said motor means through the monitoring means to maintain the flow rate of fluid through the test chamber substantially constant.
Claim 3
Dependent Claim
53 words
Fluid-sampling aparatus as in claim 1 comprising: comparator means coupled to the monitoring means for producing an output in response to the signal therefrom attaining a selected value; and means responsive to said output for producing an alarm indication which is indicative of an insufficient flow rate of fluid through the test chamber.
Claim 4
Dependent Claim
49 words
Fluid-sampling apparatus as in claim 2 comprising: storage means coupled to receive said output for storing a logic state indicative of the occurrence of an alarm indication; and accessing means coupled to the storage means for selectively interrogating the storage means to determine the occurrence of an alarm indication.
Claim 5
Dependent Claim
36 words
Fluid-sampling apparatus as in claim 3 comprising timing means connected to apply said output to the storage means for storing said logic state therein after a time interval of alarm indication determined by the timing means.
Claim 6
Independent Claim
106 words
The method of sampling a fluid by pumping fluid samples through a test chamber, the method comprising the steps of: identifying the characteristic relationship between the flow rate of fluid through the test chamber at selected differential pressures thereacross and a motive pump-energizing signal required to establish such flow rate of fluid; transforming the motive pump-energizing signal to a monitor signal according to a relationship therebetween which is representative of said characteristic relationship; and regulating the motive pump-energizing signal in response to the monitor signal to maintain the flow rate of fluid through the test chamber substantially constant over a selected range of differential pressures thereacross.
Claim 7
Independent Claim
106 words
The method of sampling a fluid by pumping fluid samples through a test chamber, the method comprising the steps of: identifying the characteristic relationship between the flow rate of fluid through the test chamber at selected differential pressures thereacross and a motive pump-energizing signal required to establish such flow rate of fluid; transforming the motive pump-energizing signal to a monitor signal according to a relationship therebetween which is representative of said characteristic relationship; and regulating the motive pump-energizing signal in response to the monitor signal to maintain the flow rate of fluid through the test chamber substantially constant over a selected range of differential pressures thereacross.
Claim 8
Dependent Claim
46 words
The method according to claim 5 comprising the steps of: detecting the condition of monitor signal attaining a value in excess of a selected limit value in response to obstruction of fluid flow through the test chamber; and providing an output indication of the detected condition.
Claim 9
Dependent Claim
30 words
The method according to claim 6 comprising the step of storing an interrogatable logic condition indicative of persistence of the detected condition for longer than a selected period of time.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-12-02 | 1984-06-02 | 1984-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-02 | 1988-06-02 | 1988-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-02 | 1992-06-02 | 1992-12-02 | $7700.00 | Window Closed / Lapsed |