GB833203A - Improvements in or relating to electric measuring instruments - Google Patents
Improvements in or relating to electric measuring instrumentsInfo
- Publication number
- GB833203A GB833203A GB535355A GB535355A GB833203A GB 833203 A GB833203 A GB 833203A GB 535355 A GB535355 A GB 535355A GB 535355 A GB535355 A GB 535355A GB 833203 A GB833203 A GB 833203A
- Authority
- GB
- United Kingdom
- Prior art keywords
- oscillator
- anode
- circuit
- capacitor
- feed
- 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
- 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
- G01N27/023—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance where the material is placed in the field of a coil
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Measurement Of Resistance Or Impedance (AREA)
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
Abstract
833,203. Impedance measurements. BRITISH ALUMINIUM CO. Ltd. Feb. 22, 1956 [Feb. 22, 1955], No. 5353/55. Class 37. [Also in Group XL (c)] In a device for determining the conductivity of a metal, a timed anode-tuned grid oscillator provided with a D.C. negative feed-back between the oscillator and the negative pole of the H.T. supply is controlled by the material under test which is associated with the grid inductance and feeds a detector stage which incorporates a meter responsive to the current passed by the stage. The sensing head, Fig. 2, comprises a dust core assembly 5 of rotated " E " section on the control core of which is wound coil L2. This assembly is mounted in a bore 3 in housing 4 and is provided with a cap 8. An enlarged bore 6 with cap 8 provides a shoulder 7 through which are three holes provided with spring-loaded balls 9 on which the housing rests. Compression spring 12 holds the individual springs 11 in position. The investigating head is connected to the measuring circuit by a coaxial cable 13 the outer conductor of which is connected to the chassis of the instrument and to spring 12 while the inner is connected to coil L2 at one end and capacitor C7 (Fig. 1) at the other. The other end of the inductor is connected to spring 12. Circuit (Fig. 1). The oscillator comprises a pentode V1 with tuned anode and tuned grid. Coil L2 in the measuring head is connected in parallel with capacitors C4, C5 and forms the tuned grid circuit. Coil L1 in the anode circuit is shunted by a finer capacitor C1 and variable capacitors C2, C3. Feed-back from the anode of V1 is through a variable capacitor C6 to the junction of C4, C5. The oscillator output feeds a detector stage comprising pentode V2 with microammeter M in its anode circuit. The heaters of V1, V2 are connected to the negative line when 5 is closed, through negative feedback resistor R4 by-passed by capacitor C11. Detector V2 is arranged to be non-conducting when the oscillator is not oscillating. The effect of the feed-back resistor is to provide a standing bias for the oscillator and, when V2 conducts to provide increased feed-back to limit the amplitude of oscillations and stabilize the oscillator.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB535355A GB833203A (en) | 1955-02-22 | 1955-02-22 | Improvements in or relating to electric measuring instruments |
| NL204747A NL112886C (en) | 1955-02-22 | 1956-02-21 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB535355A GB833203A (en) | 1955-02-22 | 1955-02-22 | Improvements in or relating to electric measuring instruments |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB833203A true GB833203A (en) | 1960-04-21 |
Family
ID=9794500
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB535355A Expired GB833203A (en) | 1955-02-22 | 1955-02-22 | Improvements in or relating to electric measuring instruments |
Country Status (2)
| Country | Link |
|---|---|
| GB (1) | GB833203A (en) |
| NL (1) | NL112886C (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2029577A (en) * | 1978-09-05 | 1980-03-19 | Coburn O | Magnetic sensor assembly |
-
1955
- 1955-02-22 GB GB535355A patent/GB833203A/en not_active Expired
-
1956
- 1956-02-21 NL NL204747A patent/NL112886C/xx active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2029577A (en) * | 1978-09-05 | 1980-03-19 | Coburn O | Magnetic sensor assembly |
| GB2029577B (en) * | 1978-09-05 | 1983-03-23 | Coburn Wesley Orin | Magnetic sensor assembly |
Also Published As
| Publication number | Publication date |
|---|---|
| NL112886C (en) | 1966-06-15 |
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