ICE DETECTION APPARATUS EMPLOYING MICROWAVE REFLECTANCE

• US 3,836,846 A
• Filed: 09/09/1971
• Issued: 09/17/1974
• Est. Priority Date: 09/09/1971
• Status: Expired due to Term

• Current Assignee: Joseph G. Dekoning, Wilson W. Overall
• Original Assignee: Joseph G. Dekoning, Wilson W. Overall
• Inventors: Overall, Wilson W., DEKoning, Joseph G.
• Primary Examiner(s): Corcoran, Robert J.
• Application Number:
  US05/178,871
• Time in Patent Office: 1,104 Days
• Field of Search: 324/58.5A,58.5B,58.5C 340/234,235
• US Class Current: 324/643
• CPC Class Codes: F25B 2700/111 using an emitter and receiver, e.g. sensing by emitting light or other radiation and receiving reflection by a sensor
• CPC Class Codes: F25D 21/02 Detecting the presence of frost or condensate
• CPC Class Codes: G01N 22/00 Investigating or analysing materials by the use of microwaves or radio waves, i.e. electromagnetic waves with a wavelength of one millimetre or more G01N3/00 - G01N17/00, G01N24/00 take precedence
• CPC Class Codes: G01W 1/14 Rainfall or precipitation gauges measuring volume in general G01F
• CPC Class Codes: G08B 19/02 Alarm responsive to formation or anticipated formation of ice

Abstract

Apparatus and method for detecting the presence of ice or water on a road or other surface by means of reflected microwaves wherein microwave energy is directed through a window installed in the surface to be monitored and the condition of the surface is indicated by the level of microwave energy reflected.

Claims

1. A system for detecting the presence of ice on a surface comprising in combination A. a microwave generator adapted to produce signal energy, B. a window in said surface substantially transparent to said signal energy, C. heating means cooperating with said window and adapted to heat said window above about 32*F., D. means for monitoring the temperature of said window in response to the action of said heating means, E. guide means adapted to convey said signal energy from said generator to said window, F. isolator means in said guide means intermediate said window and said generator, and G. reflected power detector means adapted to detect the difference between the signal energy reflected from said window at ambient temperature and that reflected from said window when heated to above about 32*F., a significant difference in reflected energy indicating that ice was initially present on said surface.

2. A method for determining the presence of ice on a surface which comprises directing microwave signal energy through a window in said surface, heating said window to above about 32*F., monitoring the window temperature during the heating step, detecting the signal energy reflected from said window at ambient temperature and that reflected from said window when heated to above about 32*F., a significant difference in reflected energy indicating that ice was initially present on said surface.