US3667280A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for determining the freezing point of a hydrocarbon
Assignee: Shell USA Inc
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Filing: 1970-07-15
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Granted: 1972-06-06
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Expires: 1990-07-15
Abstract
Abstract Method for detecting the freezing point of a hydrocarbon by placing a measured sample of the hydrocarbon in a container and placing a thermistor in the container into contact with the sample. The container is cooled until its temperature curve shows a noticeable plateau which is detected by the slope of the temperature curve which is being tracked by a first derivative circuit. The container is then insulated thus warming the sample and, as the last crystals in the sample melt, the slope of the curve momentarily accelerates causing the circuit to produce a voltage peak which is the freezing point of the sample.
Inventors
- 👤 Samuel W Simpson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:38
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/26; G01N33/28; G01N33/2811; G01N25/00; G01N25/02; G01N25/04
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
25 words
The method of claim 1 wherein the step of depositing a liquid sample in said container includes the step of depositing 25 milliliters of sample.
Claim 2
Dependent Claim
51 words
The method of claim 2 wherein the steps of cooling said sample includes the step of cooling said sample using a cooling medium of approximately -110* F., and the step of warming said container includes the step of warming said container at a rate of approximately 2* to 4* per minute.
Claim 3
Dependent Claim
33 words
The method of claim 2 wherein the step of placing said temperature measuring device in said container includes the step of placing said device in said container to substantially adjacent the bottom thereon.
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) | 1975-06-06 | 1975-12-06 | 1976-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-06 | 1979-12-06 | 1980-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-06 | 1983-12-06 | 1984-06-06 | $7700.00 | Window Closed / Lapsed |