GB1372695A - Thermal conductivity detector apparatus - Google Patents
Thermal conductivity detector apparatusInfo
- Publication number
- GB1372695A GB1372695A GB5075970A GB5075970A GB1372695A GB 1372695 A GB1372695 A GB 1372695A GB 5075970 A GB5075970 A GB 5075970A GB 5075970 A GB5075970 A GB 5075970A GB 1372695 A GB1372695 A GB 1372695A
- Authority
- GB
- United Kingdom
- Prior art keywords
- bridge
- heating current
- sensing
- terminal
- detector
- 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.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
- G01N30/02—Column chromatography
- G01N30/62—Detectors specially adapted therefor
- G01N30/64—Electrical detectors
- G01N30/66—Thermal conductivity detectors
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/14—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of an electrically-heated body in dependence upon change of temperature
- G01N27/18—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of an electrically-heated body in dependence upon change of temperature caused by changes in the thermal conductivity of a surrounding material to be tested
Landscapes
- Chemical & Material Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
- Investigating Or Analyzing Materials Using Thermal Means (AREA)
Abstract
1372695 Measuring thermal conductivity electrically PYE LTD 7 Dec 1971 [26 Oct 1970] 50759/70 Heading GIN Thermal conductivity detector apparatus for use as a gas chromatograph output detector comprises at least one sensing filament and at least one reference filament connected in a resistance bridge circuit 1 of which terminal 2 connects to the positive terminal 4 of a supply means providing heating current I H to the bridge circuit so that heating current flows in each said reference and sensing filament, and a detector 40 connected across a bridge diagonal to detect an unbalance voltage representative of a relative change in the resistances of said sensing and said reference filaments and to provide an output signal corresponding thereto, said supply means including current regulating means which regulates the heating current to the bridge in response to variations in the resistance of the bridge between the supply terminals for said heating current so as to maintain constant the mean of the temperatures of said sensing and reference filaments despite variations in the magnitude of the unbalance voltage across the detector diagonal. The heating current is controlled by the potential at the base of transistor 5 determined in turn by the potential at point 17 and thus by the voltage VK across the bridge supply terminals. Amplifier 11 inverts the input at its -ve terminal and thus exercises a negative feedback control whilst a positive feedback path by way of resistor 13 and capacitor 14 is connected between resistor 6 and the positive input terminal of amplifier 11.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB5075970A GB1372695A (en) | 1971-12-07 | 1971-12-07 | Thermal conductivity detector apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB5075970A GB1372695A (en) | 1971-12-07 | 1971-12-07 | Thermal conductivity detector apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1372695A true GB1372695A (en) | 1974-11-06 |
Family
ID=10457245
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB5075970A Expired GB1372695A (en) | 1971-12-07 | 1971-12-07 | Thermal conductivity detector apparatus |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB1372695A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2374639A1 (en) * | 1976-12-20 | 1978-07-13 | Potter Bronson M | FLUID DETECTOR |
-
1971
- 1971-12-07 GB GB5075970A patent/GB1372695A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2374639A1 (en) * | 1976-12-20 | 1978-07-13 | Potter Bronson M | FLUID DETECTOR |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed | ||
| 732 | Registration of transactions, instruments or events in the register (sect. 32/1977) | ||
| PCNP | Patent ceased through non-payment of renewal fee |