GB2234819A - Gas sensor device with sampling and oxygen mixing facilities - Google Patents
Gas sensor device with sampling and oxygen mixing facilities Download PDFInfo
- Publication number
- GB2234819A GB2234819A GB9016034A GB9016034A GB2234819A GB 2234819 A GB2234819 A GB 2234819A GB 9016034 A GB9016034 A GB 9016034A GB 9016034 A GB9016034 A GB 9016034A GB 2234819 A GB2234819 A GB 2234819A
- Authority
- GB
- United Kingdom
- Prior art keywords
- sample
- gas
- sensor device
- oxygen
- barrel
- 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.)
- Withdrawn
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/02—Devices for withdrawing samples
- G01N1/22—Devices for withdrawing samples in the gaseous state
- G01N1/24—Suction devices
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/02—Food
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- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Pathology (AREA)
- Physics & Mathematics (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Food Science & Technology (AREA)
- Molecular Biology (AREA)
- Biomedical Technology (AREA)
- Medicinal Chemistry (AREA)
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
Abstract
A gas sensor samples a predetermined volume of gas, mixes a predetermined volume of oxygen with the sample and contacts the mixture with an electrical sensor. The gas sensor may be in the form of a syringe with an electrical gas sensor 4 mounted on a plunger 2 inside the barrel 1. A stop ring 5 allows a predetermined volume of air to remain in the barrel before sampling. A gas sample may be drawn into the barrel via needle 3 upon partial withdrawal of the plunger from the barrel until stop 9 is reached. The electrical sensor may be electrochemical or a metal oxide device and may be heated, in an alternative embodiment, air is supplied through a metering valve. The sensor may be used, for example, in testing for the spoilage of packaged food since, in decaying, food produces gases such as ammonia and hydrogen sulphide. <IMAGE>
Description
Sensor Device
The present invention relates to a sensor device which finds an application in the sensing of gases produced by the spoilage of packaged foodstuffs.
According to one aspect of the present invention there is provided a sensor device comprising, means for obtaining a sample of predetermined volume of a gaseous medium to be tested for the presence of a particular gas, means for mixing a predetermined amount of oxygen with the sample of gaseous medium, means for contacting the mixture of gaseous medium and oxygen with a sensing medium which is sensitive to the said particular gas in the presence of oxygen, and means for detecting a change in a parameter of the sensing medium as a result of the presence of the particular gas in the sample of gaseous medium.
The sensor device may also be provided with a heating means, if required, to raise the gas sensor to its operating temperature if it is the type of gas sensor which requires elevated temperature operation.
The spoilage of packaged foodstuffs can give rise to, for example, hydrogen sulphide and ammonia. Thus, for example, a sensor device in accordance with the present invention may include a gas sensor which is capable of detecting hydrogen sulphide or ammonia.
In one embodiment of the present invention a sensor device for sensing a gas is in the form of a syringe arrangment including a cylindrical barrel and a cylindrical plunger, a needle for obtaining a sample of a gas or gaseous medium to be tested, a gas sensor mounted on the barrel and means for providing a predetermined amount of oxygen for admixing with the sample, the arrangement being such that upon partial withdrawal of the pluncer from the barrel a sample of gas or gaseous medium of predetermined volume is removed from a source thereof and sucked into the barrel thereby to be admixed with the predetermined amount of oxygen and brought into contact with the gas sensor.
If required the sensor device may also include a heating means, if required, to raise the gas sensor to its operating temperature if it is the type of gas sensor which requires elevated temperature operation.
In operation the presence or absence of a selected gas in the sample admixed with the predetermined amount of oxygen is detected by monitoring an electrical response of the gas sensor.
Thus, depending upon the type of gas sensor used, the electrical response of the gas sensor may be monitored by measuring, for example, a change in resistance or capacitance.
Examples of gas sensors which may be used in a sensor device in accordance with the present invention are (i) gas sensitive resistors utilising tin dioxide or tin dioxide doped with platinum, or zinc oxide, (ii) a gas sensor as disclosed in GB 2149121B or GB 2149122B or GB 2149123B or
GB 2202948A and (iii) a gas sensor as disclosed in
GB 2201787A.
The means for providing a predetermined amount of oxygen for admixing with the sample may be, for example, a stop ring in the barrel or a metering valve.
In the case of a stop ring, this may be placed at the closed end of the barrel such that the plunger cannot be fully inserted into the barrel; as will be appreciated the stop ring thus allows for the provision of a space for a predetermined volume of oxygen or an oxygen-containing gaseous mixture, such as air, to be present in the barrel prior to the introduction of the sample by withdrawal of the plunger.
Where a metering valve is used, it may be mounted on the barrel or on the plunger such that a predetermined amount as oxygen is drawn into the barrel as the plunger is withdrawn.
By way of example, in operation to detect whether, or not, spoilage of a packaged foodstuff has occurred the needle may be inserted through the wallwof the packaging material to permit a sample of the gas or gaseous medium therein to be withdrawn therefrom.
The present invention will now be further described, by way of example only, with reference to the single Figure of the accompanying drawing.
The Figure shows, in diagrammatic form, a sensor device in accordance with the present invention.
Referring now to the Figure there is shown a sensor device comprising a syringe having a cylindrical syringe barrel 1 and a cylindrical syringe plunger 2 slideably located therein. The syringe barrel 1 is provided with a hollow needle 3 and the plunger 2 carries a gas sensor 4 which incorporates a heating means (not shown).
A stop-ring 5 is provided in the barrel 1 such that the plunger 2 cannot be fully inserted therein.
Optionally a filter 6 may be provided to inhibit the ingress of liquid into the barrel 1 in operation.
Conductors (shown diagrammatically as 7 and 8) are provided to permit the electrical response of the sensor 4 to be measured; conductors (not shown) may also be provided to provide energy to heat the sensor if this is required.
Optionally an end-stop assembly represented in the
Figure as 9 may be provided so as to determine the maximum extent of withdrawal of the plunger 2 from barrel 1.
In operation the plunger 2 is partially withdrawn from the barrel 1 thereby to draw air into the barrel 1 and then the plunger 2 is inserted into the barrel 1 until it is prevented from further insertion by the stop-ring 5; a predetermined volume of air is therefore left in the barrel 1.
The needle 3 is positioned so as to be in communication with a gas or gaseous medium to be tested (e.g. by insertion through a wall of a packaging material containing a foodstuff).
The plunger 2 is withdrawn from the barrel 1 until a desired amount of sample of gas or gaseous medium has been drawn through the needle 3 and into the barrel 1 and admixed with the predetermined volume of air in the barrel 1.
The volume of sample drawn into the barrel 1 by withdrawal of the plunger 2 may, optionally, be determined by the use of an end-stop 9; this inhibits further withdrawal of the plunger 2 after a certain length of travel and this may be used instead of having to measure the volume of sample drawn into the barrel 1.
The electrical response of the gas sensor 4 is monitored (after being brought to an elevated operating temperature if required) thereby to determine whether, or not, a selected gas or gases is/are present in the sample.
Claims (7)
1. A sensor device comprising, means for obtaining a sample of predetermined volume of a gaseous medium to be tested for the presence of a particulargas, means for mixing a predetermined amount of oxygen with the sample of gaseous medium, means for contacting the mixture of gaseous medium and oxygen with a sensing medium which is sensitive to the said particular gas in the presence of oxygen, and means for detecting a change in a parameter of the sensing medium as a result of the presence of the particular gas in the sample of gaseous medium.
2. A sensor device according to claim 1 comprising a syringe including a needle a cylindrical barrel and a plunger, wherein there is included a gas sensing medium exposed to the space within the syringe, means for enabling a predetermined volume of the gaseous medium to be tested for the presence of the particular gas to be drawn into the syringe and means for mixing a predetermined volume of oxygen with the sample of gaseous medium.
3. A sensor device according to claim 2 wherein the means for mixing the predetermined volume of oxygen with the sample comprises a stop ring adapted to limit the inward travel of the plunger of the syringe.
4. A sensor device according to claim 1 or claim 2 wherein the means for mixing the predetermined volume of oxygen with the sample comprises a metering valve adapted to allow the admission of oxygen into the barrel of the syringe.
5. A sensor device according to claim 2, 3 or 4 wherein the means for admitting the predetermined volune of sample into the syringe comprises a stop arranged to limit the outward travel of the plunger of the syringe.
6. A gas sensor device according to any proceding claim including means for heating the sensing medium to an operating temperature.
7. A gas sensor device substantially as hereinbefore described and with reference to the accompanying drawing.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB898916553A GB8916553D0 (en) | 1989-07-20 | 1989-07-20 | Sensor device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB9016034D0 GB9016034D0 (en) | 1990-09-05 |
| GB2234819A true GB2234819A (en) | 1991-02-13 |
Family
ID=10660306
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB898916553A Pending GB8916553D0 (en) | 1989-07-20 | 1989-07-20 | Sensor device |
| GB9016034A Withdrawn GB2234819A (en) | 1989-07-20 | 1990-07-20 | Gas sensor device with sampling and oxygen mixing facilities |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB898916553A Pending GB8916553D0 (en) | 1989-07-20 | 1989-07-20 | Sensor device |
Country Status (1)
| Country | Link |
|---|---|
| GB (2) | GB8916553D0 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2018202416A1 (en) * | 2017-05-04 | 2018-11-08 | Arcelik Anonim Sirketi | A food spoilage detector with gas sensor |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110646252A (en) * | 2019-09-27 | 2020-01-03 | 沈阳农业大学 | Dry-wet alternation rice field is with portable timing multiple spot ammonia sampling device that volatilizees |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1105046A (en) * | 1965-09-08 | 1968-03-06 | Westfaelische Berggewerkschaft | Instruments and methods for measuring the carbon monoxide content of combustion engine exhaust gases |
| GB2025065A (en) * | 1978-07-05 | 1980-01-16 | Sclavo Inst Sieroterapeut | Electrochemical sensing device |
| GB2118722A (en) * | 1982-03-16 | 1983-11-02 | Kanegafuchi Chemical Ind | A method for measuring the concentration of a combustible component |
-
1989
- 1989-07-20 GB GB898916553A patent/GB8916553D0/en active Pending
-
1990
- 1990-07-20 GB GB9016034A patent/GB2234819A/en not_active Withdrawn
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1105046A (en) * | 1965-09-08 | 1968-03-06 | Westfaelische Berggewerkschaft | Instruments and methods for measuring the carbon monoxide content of combustion engine exhaust gases |
| GB2025065A (en) * | 1978-07-05 | 1980-01-16 | Sclavo Inst Sieroterapeut | Electrochemical sensing device |
| GB2118722A (en) * | 1982-03-16 | 1983-11-02 | Kanegafuchi Chemical Ind | A method for measuring the concentration of a combustible component |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2018202416A1 (en) * | 2017-05-04 | 2018-11-08 | Arcelik Anonim Sirketi | A food spoilage detector with gas sensor |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8916553D0 (en) | 1989-09-06 |
| GB9016034D0 (en) | 1990-09-05 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |