Microwave ice accretion measuring instrument
First Claim
1. An instrument for detecting the presence of and measuring the thickness of ice at a measuring location comprising:
- a waveguide located to have its characteristics varied subject to ice accretion at said measuring location, said waveguide having an input port and a separate output port,a controllable oscillator with a control input and an output, means connecting said output of said controllable oscillator to said waveguide input port,sweep means connected to said control input to provide a control signal to cause said controllable oscillator to sweep in frequency as a function of time,detecting means connected to said output port to provide a detection signal with at least one parameter varying as a function of time and related to energy received by said detecting means at said output port,peaking means responsive to said detecting means to provide a peaking signal with recognizable transitions corresponding to predetermined points of said detection signal, andcomputing means responsive to said peaking signal for detecting ice presence and thickness at said measuring location.
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Accused Products
Abstract
An ice measurement instrument includes a waveguide operating in a transmission mode passing energy from an input port to an output port. The resonant frequency of the waveguide depends on the presence and/or thickness of ice at a measuring location. The energy applied to the input port is swept in frequency from a first frequency to a second frequency at or above an ice-free resonant frequency of said waveguide, and back to said first frequency. Energy received at the output port is peak detected to provide a detection signal with four recognizable transitions identifying a pair of peaks which correspond to the resonant frequency of the waveguide. The time delay between these peaks can be used, in comparison with the time delay corresponding to an ice-free condition, to determine ice thickness.
36 Citations
29 Claims
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1. An instrument for detecting the presence of and measuring the thickness of ice at a measuring location comprising:
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a waveguide located to have its characteristics varied subject to ice accretion at said measuring location, said waveguide having an input port and a separate output port, a controllable oscillator with a control input and an output, means connecting said output of said controllable oscillator to said waveguide input port, sweep means connected to said control input to provide a control signal to cause said controllable oscillator to sweep in frequency as a function of time, detecting means connected to said output port to provide a detection signal with at least one parameter varying as a function of time and related to energy received by said detecting means at said output port, peaking means responsive to said detecting means to provide a peaking signal with recognizable transitions corresponding to predetermined points of said detection signal, and computing means responsive to said peaking signal for detecting ice presence and thickness at said measuring location. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A method of detecting the presence and thickness of ice at a measuring location comprising:
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providing a waveguide located to have its electrical characteristics varied, subject to ice accretion at the measuring location, the waveguide being provided with an input port and separate output port, energizing the waveguide with electrical energy, at its input port, said electrical energy sweeping in frequency as a function of time, peak detecting energy received at said output port of said waveguide to provide a peaking signal with recognizable transitions corresponding to energy received at said output port of said waveguide, and determining from said recognizable transitions, ice presence and ice thickness at said measuring location. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29)
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Specification