GB2259768A - Apparatus for determining the life time of a material which varies with temperature - Google Patents

Apparatus for determining the life time of a material which varies with temperature Download PDF

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Publication number
GB2259768A
GB2259768A GB9120198A GB9120198A GB2259768A GB 2259768 A GB2259768 A GB 2259768A GB 9120198 A GB9120198 A GB 9120198A GB 9120198 A GB9120198 A GB 9120198A GB 2259768 A GB2259768 A GB 2259768A
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GB
United Kingdom
Prior art keywords
life
temperature
sample
time
monitoring apparatus
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB9120198A
Other versions
GB2259768B (en
GB9120198D0 (en
Inventor
Peter J Holness
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BAE Systems PLC
Original Assignee
British Aerospace PLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by British Aerospace PLC filed Critical British Aerospace PLC
Priority to GB9120198A priority Critical patent/GB2259768B/en
Publication of GB9120198D0 publication Critical patent/GB9120198D0/en
Publication of GB2259768A publication Critical patent/GB2259768A/en
Application granted granted Critical
Publication of GB2259768B publication Critical patent/GB2259768B/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01M—LUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING
    • F01M11/00—Component parts, details or accessories, not provided for in, or of interest apart from, groups F01M1/00 - F01M9/00
    • F01M11/10—Indicating devices; Other safety devices
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N17/00—Investigating resistance of materials to the weather, to corrosion, or to light
    • G—PHYSICS
    • G07—CHECKING-DEVICES
    • G07C—TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE
    • G07C3/00—Registering or indicating the condition or the working of machines or other apparatus, other than vehicles
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16N—LUBRICATING
    • F16N2200/00—Condition of lubricant
    • F16N2200/02—Oxidation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16N—LUBRICATING
    • F16N2230/00—Signal processing
    • F16N2230/02—Microprocessor; Microcomputer

Abstract

Apparatus for monitoring life-time of chemical compounds (2) that deteriorate with time and at a rate that varies with temperature comprises means for monitoring the temperature of a sample of the compound, a memory (4) for storing temperature/life time characteristics of the compound and data processing means (3) for calculating the life time from the temperature measurements and stored data using the Arrhenius equation. The predicted life time is displayed on a VDU (6). <IMAGE>

Description

LIFE MONITORING APPARATUS This invention relates to apparatus for monitoring the life-time of items which deteriorate over time.
A "reaction rate" ( t ) for a chemical compound, for example, can be written as a function of temperature as follows:
where t is a proportional constant is is an activation energy is is the universal gas constant, and T the absolute temperature of a sample.
The above equation is known as the Arrhenius equation and is well known.
It can be seen from the equation that the higher the temperature of the sample, the greater the reaction rate.
It is also known that i is inversely proportional to the life-time of a sample. Therefore, the lower the temperature, the longer the life.
Prediction of the life-time of a sample can be made from look-up tables relating storage temperature to life-time. However, such tables cannot account for fluctuations in storage temperature and therefore under such conditions cannot give an accurate prediction.
An object of this invention is to provide an automated life-monitoring apparatus which takes into account any fluctuations in temperature of the sample.
Thus the invention consists of life monitoring apparatus for a sample, said apparatus comprising: a sensor for monitoring temperature values of the sample; a memory for storing life-time data and temperature data relating to the sample; and a signal processor for calculating sample life-time from said temperature values and said life-time data.
The temperature sensor may be a thermocouple or solid state device for example and could be located close to or embedded in the sample. The output from the sensor could be hard-wired into the signal processor or transmitted over a telemetry link.
The calculated life-time output from the signal processor could be displayed on a visual display unit or fed into a data processing unit for further processing.
An embodiment of the invention will now be described, by way of example only with reference to the drawing which is a block diagram of apparatus for monitoring the life of an item.
A thermocouple 1 is embedded in a sample 2 consisting of a chemical compound. The output of the thermocouple 1 is connected to a signal processor 3. Also connected to the signal processor 3 is a memory 4, a store 5 and a visual display unit (VDU) 6.
From equation (1) and by making the substitution
it can be shown that EA I tl c 61 t (2 where t1 and t2 are the life times of a sample held at temperatures T1 and T2 respectively, and k1 and k2 are the reaction rates of a sample at temperatures T1 and T2 respectively.
The signal processor is programmed to calculate t2 given tl obtained from look-up tables stored in the memory 4 and from consecutive temperature readings T1 and T2 obtained from the thermocouple 1.
The apparatus shown in the drawing operates as follows: For a given known substance (sample 1) data relating temperature of sample to life time are entered into the memory 4 and stored permanently therein. The signal processor 3 then latches in a reading T1 from the thermocouple and interrogates the memory 4 for the life-time tl corresponding to temperature T1. The values tl and T1 are then put into the (temporary) store 5 and tl is displayed on the VDU 6. After some predetermined time (which could be an hour, say, depending on how rapid ambient temperature fluctuations may be) the signal processor 3 latches in a second reading T2 from the thermocouple 1.
Using the stored values of t1 and T1 and the measured value T2, the signal processor calculates t2 by solving equation 2. The new life-time value t2 is then displayed on the VDU 6 and the values t2 and T2 are stored in the store 5. The process described above is then continued for subsequent measurements of temperature. In general terms, the equation (2) solved by the signal processor 3 can be written:
where t is an integer.
The signal processor 3 may, optionally be provided with circuitry for signalling an alarm if any temperature reading exceeds a given limit, or a given rate of increase or decrease.

Claims (6)

1. Life monitoring apparatus for a sample in which said apparatus comprises: a sensor for monitoring temperature values of the sample; a memory for storing life-time data and temperature data relating to the sample; and a signal processor for calculating sample life-time from said temperature value and said life-time data.
2. Life monitoring apparatus according to claim 1 in which the signal processor is adapted to solve the equation:
where t is an integer is a life-time is is a temperature is is an activation energy, and R is the universal gas constant.
3. Life monitoring apparatus according to any preceding claim and further comprising a visual display unit for displaying a sample life-time calculated by the signal processor.
4. Life monitoring apparatus according to any preceding claim in which the temperature sensor is a thermocouple.
5. Life monitoring apparatus according to any of claims 1 to 3 in which the temperature sensor is a solid state device.
6. Life monitoring apparatus substantially as hereinbefore described with reference to the drawing.
GB9120198A 1991-09-21 1991-09-21 Life monitoring apparatus for a sample Expired - Lifetime GB2259768B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB9120198A GB2259768B (en) 1991-09-21 1991-09-21 Life monitoring apparatus for a sample

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB9120198A GB2259768B (en) 1991-09-21 1991-09-21 Life monitoring apparatus for a sample

Publications (3)

Publication Number Publication Date
GB9120198D0 GB9120198D0 (en) 1991-11-06
GB2259768A true GB2259768A (en) 1993-03-24
GB2259768B GB2259768B (en) 1995-01-04

Family

ID=10701803

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9120198A Expired - Lifetime GB2259768B (en) 1991-09-21 1991-09-21 Life monitoring apparatus for a sample

Country Status (1)

Country Link
GB (1) GB2259768B (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1319928A1 (en) * 2001-12-14 2003-06-18 3M Innovative Properties Company Indicator for perishable goods with preceding period data input, interrupt, variable recording, Arrhenius equation, data transmission
EP1359395A2 (en) * 2002-04-29 2003-11-05 Hewlett-Packard Company Determination of pharmaceutical expiration date
US7392150B2 (en) 2001-12-14 2008-06-24 3M Innovative Properties Company Environmental parameter indicator for perishable goods
CN103470521A (en) * 2013-09-26 2013-12-25 海南金盘电气有限公司 Fan life prediction device
US9710754B2 (en) 2012-10-09 2017-07-18 Infratab, Inc. Inference electronic shelf life dating system for perishables
US9946904B2 (en) 2004-04-27 2018-04-17 Infratab, Inc. Apparatus and method for monitoring and communicating data associated with a product
DE102019219248A1 (en) * 2019-12-10 2021-06-10 Robert Bosch Gmbh Method and diagnostic device for determining an operating time of a device

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0231055A2 (en) * 1986-01-27 1987-08-05 General Motors Corporation A method of indicating the need for engine oil change

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0231055A2 (en) * 1986-01-27 1987-08-05 General Motors Corporation A method of indicating the need for engine oil change

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1319928A1 (en) * 2001-12-14 2003-06-18 3M Innovative Properties Company Indicator for perishable goods with preceding period data input, interrupt, variable recording, Arrhenius equation, data transmission
WO2003052354A1 (en) * 2001-12-14 2003-06-26 3M Innovative Properties Company Environmental parameter indicator for perishable goods
US7392150B2 (en) 2001-12-14 2008-06-24 3M Innovative Properties Company Environmental parameter indicator for perishable goods
EP1359395A2 (en) * 2002-04-29 2003-11-05 Hewlett-Packard Company Determination of pharmaceutical expiration date
EP1359395A3 (en) * 2002-04-29 2005-11-23 Hewlett-Packard Company Determination of pharmaceutical expiration date
US9946904B2 (en) 2004-04-27 2018-04-17 Infratab, Inc. Apparatus and method for monitoring and communicating data associated with a product
US9710754B2 (en) 2012-10-09 2017-07-18 Infratab, Inc. Inference electronic shelf life dating system for perishables
CN103470521A (en) * 2013-09-26 2013-12-25 海南金盘电气有限公司 Fan life prediction device
CN103470521B (en) * 2013-09-26 2016-03-23 海南金盘电气有限公司 Fan life prediction device
DE102019219248A1 (en) * 2019-12-10 2021-06-10 Robert Bosch Gmbh Method and diagnostic device for determining an operating time of a device

Also Published As

Publication number Publication date
GB2259768B (en) 1995-01-04
GB9120198D0 (en) 1991-11-06

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Legal Events

Date Code Title Description
732E Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977)
PE20 Patent expired after termination of 20 years

Expiry date: 20110920