Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
91 words
A method for detecting ice on a surface of a thin solid sheet comprising, energising a transducer to cause propagation through a portion of the sheet of ultrasonic waves having their predominant component parallel to the surface of the sheet, detecting the waves by means of a second transducer, measuring the amplitude of the waves received by the second transducer, and detecting by means of the amplitude of the waves received by the second transducer the presence of a layer of ice on the surface of the portion of the sheet.
Claim 2
Independent Claim
91 words
A method for detecting ice on a surface of a thin solid sheet comprising, energising a transducer to cause propagation through a portion of the sheet of ultrasonic waves having their predominant component parallel to the surface of the sheet, detecting the waves by means of a second transducer, measuring the amplitude of the waves received by the second transducer, and detecting by means of the amplitude of the waves received by the second transducer the presence of a layer of ice on the surface of the portion of the sheet.
Claim 3
Dependent Claim
16 words
A method as claimed in claim 1 wherein the waves are horizontally polarized guided shear waves.
Claim 4
Dependent Claim
21 words
A method as claimed in claim 1 wherein the waves are a mode of Lamb wave whose predominant component is horizontal.
Claim 5
Dependent Claim
26 words
A method as claimed in claim 1 wherein the frequency of the waves is chosen to provide a desired sensitivity to thickness of the ice layer.
Claim 6
Dependent Claim
82 words
An ice detector to detect ice on a surface of a thin solid sheet, comprising an ultrasonic transducer adapted to cause propagation through a portion of the sheet of ultrasonic waves having their predominant component parallel to the surface of the sheet, an ultrasonic transducer adapted to receive the waves and create a signal representative of the amplitude thereof, and means responsive to the signal to detect the presence of an ice layer on the surface of the portion of the sheet.
Claim 7
Dependent Claim
82 words
An ice detector to detect ice on a surface of a thin solid sheet, comprising an ultrasonic transducer adapted to cause propagation through a portion of the sheet of ultrasonic waves having their predominant component parallel to the surface of the sheet, an ultrasonic transducer adapted to receive the waves and create a signal representative of the amplitude thereof, and means responsive to the signal to detect the presence of an ice layer on the surface of the portion of the sheet.
Claim 8
Dependent Claim
17 words
An ice detector as claimed in claim 5 wherein the waves are horizontally polarized guided shear waves.
Claim 9
Dependent Claim
22 words
An ice detector as claimed in claim 5 wherein the waves are a mode of Lamb wave whose predominant component is horizontal.
Claim 10
Dependent Claim
27 words
An ice detector as claimed in claim 5 wherein the frequency of the waves is chosen to provide a desired sensitivity to thickness of the ice layer.
Claim 11
Dependent Claim
34 words
An ice detector as claimed in claim 5 wherein the ultrasonic transducers are acoustically coupled to the opposite surface of the portion of the sheet to that on which an ice layer may form.
Claim 12
Dependent Claim
15 words
An ice detector as claimed in claim 5 wherein the ultrasonic transducers are piezoelectric transducers.
Claim 13
Dependent Claim
31 words
An ice detector as claimed in claim 10 wherein each transducer includes at least six piezoelectric strips parallel to one another and parallel and adjacent to the surface of the sheet.
Claim 14
Dependent Claim
15 words
An ice detector as claimed in claim 5 wherein the ultrasonic transducers are electromagnetic transducers.
Claim 15
Dependent Claim
35 words
An ice detector as claimed in claim 12 wherein each transducer comprises at least six ferromagnetic strips parallel to one another and parallel and adjacent to the surface of the sheet, and an exciting coil.
Claim 16
Dependent Claim
192 words
An ice detector to detect ice on a surface of a thin solid sheet comprising: (a) a first ultrasonic transducer acoustically coupled to the surface of the sheet opposite to the surface on which an ice layer may form, and adapted when energised to cause propagation through a portion of the sheet of horizontally polarized guided ultrasonic shear waves of a frequency between 250 kHz and 1 MHz; (b) a second ultrasonic transducer acoustically coupled to the said opposite surface of the sheet, and adapted to receive the ultrasonic waves propagating through the portion of the sheet and to create a signal representative of the amplitude of said ultrasonic waves; and (c) means responsive to the signal to detect the presence of an ice layer on the surface of the portion of the sheet; wherein the frequency is chosen to provide a desired sensitivity to thickness of the ice layer, and each transducer comprises a plurality of linear transducer elements arranged adjacent to the said opposite surface, aligned parallel to each other at a spacing about equal to the wavelength of the ultrasonic waves of the chosen frequency propagating in the sheet.
Claim 17
Dependent Claim
192 words
An ice detector to detect ice on a surface of a thin solid sheet comprising: (a) a first ultrasonic transducer acoustically coupled to the surface of the sheet opposite to the surface on which an ice layer may form, and adapted when energised to cause propagation through a portion of the sheet of horizontally polarized guided ultrasonic shear waves of a frequency between 250 kHz and 1 MHz; (b) a second ultrasonic transducer acoustically coupled to the said opposite surface of the sheet, and adapted to receive the ultrasonic waves propagating through the portion of the sheet and to create a signal representative of the amplitude of said ultrasonic waves; and (c) means responsive to the signal to detect the presence of an ice layer on the surface of the portion of the sheet; wherein the frequency is chosen to provide a desired sensitivity to thickness of the ice layer, and each transducer comprises a plurality of linear transducer elements arranged adjacent to the said opposite surface, aligned parallel to each other at a spacing about equal to the wavelength of the ultrasonic waves of the chosen frequency propagating in the sheet.