Patent US2657870A successfully refreshed from Google Patents.
Patent US4398863A successfully refreshed from Google Patents.
US3793180A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Laser-recticle electrophoresis instrument
Assignee: Singer Co
•
Filing: 1972-03-21
•
Granted: 1974-02-19
•
Expires: 1992-03-21
Abstract
Abstract An improved instrument is provided for measuring electrophoretic mobility by reticle velocity measurements of laser illuminated particles. The instrument of the invention finds particular utility in industrial processing of colloidal suspensions, and particularly in the purification of industrial and drinking water. A laser beam is provided in the instrument of the invention which is focused on the particles in the sample solution which is contained in an electrophoretic cell. A reticle or grating is positioned such that the reflection of the laser beam from the particles passes through the reticle to a phototube placed on the other side of the reticle. Then, as the particles move through the solution the photo-tube is intermittently illuminated through the reticle and, as a result, generates a train of electric pulses whose frequency is directly proportional to the velocity of the particles, and is therefore a measure of electrophoretic mobility.
Inventors
- 👤 R Flower
- 👤 I Greenwood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:35
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/416; G01N27/447; G01N27/44704; G01N27/44717; G01N27/44721
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
127 words
An instrument for measuring the electrophoretic mobility of particles dispersed in a liquid and under the influence of an electric field, said instrument including: an electrophoretic cell for receiving and holding a liquid sample having electrophoretic particles therein and in which said particles migrate under the influence of an electric field; ''means for illuminating the particles migrating in said sample by a light beam; a microscope positioned to receive the light beam from the cell; an optical grating positioned in the optical path from said microscope to modulate the light beam in accordance with movement of said migrating particles; and photodetector means positioned to receive the modulated light beam from said grating for producing electric pulses having a frequency related to the velocity of said migrating particles.
Claim 2
Dependent Claim
127 words
An instrument for measuring the electrophoretic mobility of particles dispersed in a liquid and under the influence of an electric field, said instrument including: an electrophoretic cell for receiving and holding a liquid sample having electrophoretic particles therein and in which said particles migrate under the influence of an electric field; ''means for illuminating the particles migrating in said sample by a light beam; a microscope positioned to receive the light beam from the cell; an optical grating positioned in the optical path from said microscope to modulate the light beam in accordance with movement of said migrating particles; and photodetector means positioned to receive the modulated light beam from said grating for producing electric pulses having a frequency related to the velocity of said migrating particles.
Claim 3
Dependent Claim
35 words
The instrument defined in claim 1, in which said electrophoretic cell has a passage therein for the electrophoretic migration of said particles, and in which said illuminating means illuminates the particles migrating in said passage.
Claim 4
Dependent Claim
16 words
The instrument defined in claim 1, in which said illuminating means comprises a laser light source.
Claim 5
Dependent Claim
28 words
The instrument defined in claim 1, in which said photodetector means produces said pulses with an amplitude related to the size of said migrating particles in said cell.
Claim 6
Dependent Claim
40 words
The instrument defined in claim 1, and which includes computing means coupled to said photodetector means for computing the velocity and Zeta potential for each migrating particle in response to the frequency of the electric pulses from said photo-detector means.
Claim 7
Dependent Claim
31 words
The instrument defined in claim 5, in which said computing means responds to the amplitude of the pulses received from said photodetector means to compute the size of said migrating particles.
Claim 8
Dependent Claim
32 words
The instrument defined in claim 6, in which said computing means includes means for counting the aforesaid particles per unit time to compute the total number of particles within a volume unit.
References Cited (Backward Citations)
US2412602A
Cited
US2379158A
Cited
US2494441A
Cited
US3320148A
Cited
US3454487A
Cited
US3498905A
Cited
US3523733A
Cited
US3519353A
Cited
US3511227A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-18 | 1977-08-20 | 1978-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-18 | 1981-08-20 | 1982-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-18 | 1985-08-20 | 1986-02-19 | $7700.00 | Window Closed / Lapsed |