DIELECTRIC CONSTANT-TYPE RESISTANCE-INSENSITIVE DIRECT-READING WATER CONTENT METER
First Claim
1. A dielectric constant type resistance-insensitive directreading meter for measuring the water content in a test sample comprising:
- a high-frequency oscillator of angular frequency omega having a source internal resistance rp, said oscillator including a tank circuit having a coil of self-inductance Lo;
a measuring circuit including a detecting section and a measuring section connected to one another, said detecting section comprising a first voltage pickup coil having a selfinductance lo, which first pickup coil is coupled to coil Lo of said tank circuit through a mutual induction Mo, a transformer primary coil having a self-inductance lx connected in series with coil lo, and a variable capacitor having a capacitance Ce connected in parallel with said series connected elements lo and lx, said measuring section comprising a main coil and a variable capacitor to be connected in parallel with the test sample; and
a phase discriminator including a secondary coil of said transformer connected to a second voltage pickup coil for monitoring phase deviations in voltages detected through said transformer due to the connection of the test sample to said measuring section;
the respective values of Mo and Ce satisfying the condition where, R1 represents the series resistance of the coils in said detecting section, rt represents the series resistance of said measuring section, and l1 is the sum of lo and lx.
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Abstract
A dielectric constant-type resistance-insensitive direct-reading electrical apparatus for measuring water content wherein a measuring circuit coupled to a coil of a tank circuit in a highfrequency oscillator through a mutual induction coefficient Mo comprises a series connection of a voltage pickup coil, a coil for taking out a detected voltage, a main coil and a first variable capacitor. A second variable capacitor Ce is connected to the junction between the said coil for taking out a detected voltage and the main coil, and the respective values of Mo and Ce, are suitably chosen to maintain a particular relation among the circuit constants so that a phase deviation of the detected voltage due to the connection of a test sample in parallel with the said first variable capacitor may be detected through a phase discriminator without the influence of the resistive component of the test sample.
3 Citations
1 Claim
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1. A dielectric constant type resistance-insensitive directreading meter for measuring the water content in a test sample comprising:
- a high-frequency oscillator of angular frequency omega having a source internal resistance rp, said oscillator including a tank circuit having a coil of self-inductance Lo;
a measuring circuit including a detecting section and a measuring section connected to one another, said detecting section comprising a first voltage pickup coil having a selfinductance lo, which first pickup coil is coupled to coil Lo of said tank circuit through a mutual induction Mo, a transformer primary coil having a self-inductance lx connected in series with coil lo, and a variable capacitor having a capacitance Ce connected in parallel with said series connected elements lo and lx, said measuring section comprising a main coil and a variable capacitor to be connected in parallel with the test sample; and
a phase discriminator including a secondary coil of said transformer connected to a second voltage pickup coil for monitoring phase deviations in voltages detected through said transformer due to the connection of the test sample to said measuring section;
the respective values of Mo and Ce satisfying the condition where, R1 represents the series resistance of the coils in said detecting section, rt represents the series resistance of said measuring section, and l1 is the sum of lo and lx.
- a high-frequency oscillator of angular frequency omega having a source internal resistance rp, said oscillator including a tank circuit having a coil of self-inductance Lo;
Specification
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- Resources
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Current AssigneeBunjiro Ichijo
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Original AssigneeBunjiro Ichijo
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InventorsIchijo, Bunjiro
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Primary Examiner(s)Kubasiewicz, Edward E.
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Application NumberUS05/001,173Time in Patent Office685 DaysField of Search324/60,61US Class Current324/664CPC Class CodesG01R 27/2623 Measuring-systems or electr...
