US3638495A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for detecting aging of articles
Assignee: Dynametric Inc
•
Filing: 1968-08-07
•
Granted: 1972-02-01
•
Expires: 1988-08-07
Abstract
Abstract An age indicator which indicates the effect of temperature on the useful life of articles, particularly unused photosensitive sheet material, is exposed to the same temperature conditions as the article itself. The age indicator deposits metal or other material by electrochemical deposition in accordance with Faraday''s law. The rate of deposition is made proportional to the known aging rate of the article at various temperatures, so that a correct indication of aging can be obtained even though the article is exposed to unknown, widely variable, temperature conditions. The age indicator is conveniently placed in close proximity to the article, such as inside a container with the article, thereby being exposed to the same unknown, widely variable, temperature conditions as the article itself. Such temperatures occur, for example, in the transportation or storage of articles through or in zones of extremely high temperatures. During the period of exposure, the age indicator will provide an indication of the remaining or consumed useful life of the article.
Inventors
- 👤 Donald R Sessler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:28
CPC Classifications
G; G01; G01K; G01K3/00; G01K3/02; G01K3/04
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
254 words
In a method of accurately indicating the cumulative aging effects of temperature on the useful life of photosensitive material by means of an electrochemical age indicator, which photosensitive material is characterized by an aging rate which varies as a function of temperature and whicH is shipped from one point to another over a course along which the photosensitive material is exposed to unknown and variable temperature conditions, including some involving long durations at high atmospheric-temperature conditions, the steps of: inserting said electrochemical device into a container with said photosensitive material, exposing said container together with its contents to variable temperature conditions, including some high atmospherictemperature conditions, during shipment, continually detecting changes in the temperature inside of said container such shipment, continually developing an electrical current in said electrochemical device during such shipment, continually adjusting the magnitude of the current in accordance with the detected temperature to cause the current to vary in proportion to the aging rate of said photosensitive material, depositing a material in said electrochemical device at a rate proportional to the current during the shipment, measuring the amount of material that was deposited during the course of the shipment to provide an indication of the exact extent to which the photosensitive material has aged during the period of shipment, the measurement being made at the termination of said exposure to ascertain whether the specified life has been consumed; and then testing a limited portion of said photosensitive material to determine whether the actual useful life of the material has been consumed.
Claim 2
Dependent Claim
254 words
In a method of accurately indicating the cumulative aging effects of temperature on the useful life of photosensitive material by means of an electrochemical age indicator, which photosensitive material is characterized by an aging rate which varies as a function of temperature and whicH is shipped from one point to another over a course along which the photosensitive material is exposed to unknown and variable temperature conditions, including some involving long durations at high atmospheric-temperature conditions, the steps of: inserting said electrochemical device into a container with said photosensitive material, exposing said container together with its contents to variable temperature conditions, including some high atmospherictemperature conditions, during shipment, continually detecting changes in the temperature inside of said container such shipment, continually developing an electrical current in said electrochemical device during such shipment, continually adjusting the magnitude of the current in accordance with the detected temperature to cause the current to vary in proportion to the aging rate of said photosensitive material, depositing a material in said electrochemical device at a rate proportional to the current during the shipment, measuring the amount of material that was deposited during the course of the shipment to provide an indication of the exact extent to which the photosensitive material has aged during the period of shipment, the measurement being made at the termination of said exposure to ascertain whether the specified life has been consumed; and then testing a limited portion of said photosensitive material to determine whether the actual useful life of the material has been consumed.
Claim 3
Dependent Claim
253 words
In a method of accurately indicating the cumulative aging effects of temperature on the useful life of an article composed of material subject to aging by means of an electrochemical age indicator, which material is characterized by an aging rate which varies as a function of temperature and which is shipped from one point to another over a course along which the material is exposed to unknown and variable temperature conditions, including some involving long durations at high atmospheric-temperature conditions, the steps of: inserting said electrochemical device into a container with said material, exposing said container together with its contents to variable temperature conditions, including some high atmospheric-temperature conditions, during shipment, continually detecting changes in the temperature inside of said container during such shipment, continually developing an electrical current in said electrochemical device during such shipment, continually adjusting the magnitude of the current in accordance with the detected temperature to cause the current to vary in proportion to the aging rate of said material, depositing a material in said electrochemical device at a rate proportional to the current during the shipment, measuring the amount of material that was deposited during the course of the shipment to provide an indication of the extent to which the material has aged during the period of shipment, the measurement being made at the termination of said exposure to ascertain whether the specified life has been consumed; and testing a limited portion of said material to determine whether the actual useful life of the material has been consumed.
Claim 4
Dependent Claim
253 words
In a method of accurately indicating the cumulative aging effects of temperature on the useful life of an article composed of material subject to aging by means of an electrochemical age indicator, which material is characterized by an aging rate which varies as a function of temperature and which is shipped from one point to another over a course along which the material is exposed to unknown and variable temperature conditions, including some involving long durations at high atmospheric-temperature conditions, the steps of: inserting said electrochemical device into a container with said material, exposing said container together with its contents to variable temperature conditions, including some high atmospheric-temperature conditions, during shipment, continually detecting changes in the temperature inside of said container during such shipment, continually developing an electrical current in said electrochemical device during such shipment, continually adjusting the magnitude of the current in accordance with the detected temperature to cause the current to vary in proportion to the aging rate of said material, depositing a material in said electrochemical device at a rate proportional to the current during the shipment, measuring the amount of material that was deposited during the course of the shipment to provide an indication of the extent to which the material has aged during the period of shipment, the measurement being made at the termination of said exposure to ascertain whether the specified life has been consumed; and testing a limited portion of said material to determine whether the actual useful life of the material has been consumed.
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) | 1975-01-31 | 1975-08-02 | 1976-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-31 | 1979-08-02 | 1980-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-31 | 1983-08-02 | 1984-02-01 | $7700.00 | Window Closed / Lapsed |