Patent US1892603A successfully refreshed from Google Patents.
Patent US4307987A successfully refreshed from Google Patents.
US5506507A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for measuring ions in a clean room gas flow using a spherical electrode
Assignee: Hugle Electronics Inc
•
Filing: 1993-09-17
•
Granted: 1996-04-09
•
Expires: 2013-09-17
Abstract
Abstract An apparatus for measuring ions in a gas which has a sensor around which the gas flows, the ions giving off their charge and giving rise to a current. The sensor is constructed as an electrode with a flow-favorable shape, such as a sphere. A fixed voltage is impressed on the electrode and the current produced at the electrode is measured, evaluated in a circuit and constitutes a measure for the ion count.
Inventors
- 👤 Jorg Schwierzke
- 👤 Hans-Henrich Stiehl
- 👤 Joachim Lohr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 00:47
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/62
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
79 words
An apparatus for measuring ions in a gas flowing in a substantially field free environment using a sensor around which the gas flows, the ions giving off their charge, and with an electrical circuit for evaluating the current caused by the charges, characterized in that the sensor is constructed as an electrode with a flow-favorable shape with a fixed voltage of changing polarity impressed on the electrode, and that the current is filtered with a low critical frequency filter.
Claim 2
Independent Claim
79 words
An apparatus for measuring ions in a gas flowing in a substantially field free environment using a sensor around which the gas flows, the ions giving off their charge, and with an electrical circuit for evaluating the current caused by the charges, characterized in that the sensor is constructed as an electrode with a flow-favorable shape with a fixed voltage of changing polarity impressed on the electrode, and that the current is filtered with a low critical frequency filter.
Claim 3
Dependent Claim
13 words
The apparatus according to claim 1, characterized in that the electrode is spherical.
Claim 4
Dependent Claim
58 words
The apparatus according to claim 1, characterized in that a negative voltage is impressed on the electrode for measuring the number of positive ions, a positive voltage is impressed on the electrode for measuring the number of negative ions and a zero voltage relative to the reference potential is impressed on the electrode for measuring the ion balance.
Claim 5
Dependent Claim
16 words
The apparatus according to claim 1, characterized in that the electric circuit has a current-voltage converter.
Claim 6
Dependent Claim
37 words
The apparatus according to claim 3, characterized in that a switch controlled by a control unit is provided and by means of said switch and in a cyclic manner the different voltages are impressed on the electrode.
Claim 7
Dependent Claim
26 words
The apparatus according to claim 4, characterized in that the current-voltage converter is constructed as an operational amplifier with a resistor in a negative feedback branch.
Claim 8
Dependent Claim
45 words
The apparatus according to claim 1, characterized in that the ion count is determined by the electric circuit for evaluating the current caused by the charges and that a threshold value-storing comparing circuit is provided which compares the measured ion counts with the threshold values.
Claim 9
Dependent Claim
34 words
The apparatus according to claim 1, characterized in that an integrator for the up-slope integration of the current supplied by the electrode is provided and is in each case reset after fixed time intervals.
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) | 1999-04-09 | 1999-10-09 | 2000-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-04-09 | 2003-10-09 | 2004-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-04-09 | 2007-10-09 | 2008-04-09 | $7700.00 | Window Closed / Lapsed |