Coal-shale interface detection

US4154084A · kind A · utility

Assignee

• The United States of America as represented by the Administrator of the National Aeronautics and Space Administration · US

Inventors

• Peter H. Broussard · Huntsville, US
• John L. Burch · Decatur, US
• Edward Drost · Skokie, US
• Richard J. Stein · Huntsville, US

Key dates

• Filing date: Nov 3, 1977
• Grant date: May 15, 1979
• Expiry date: Nov 3, 1997

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N3/48
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A penetrometer for coal-shale interface detection for use with coal cutting equipment consisting of a reciprocating hammer having an accelerometer mounted thereon to measure the impact of the hammer as it penetrates the ceiling or floor surface of a mine. Additionally, a pair of reflectometers simultaneously view the same surface, and the outputs from the accelerometer and reflectometers are detected and jointly registered to determine when an interface between coal and shale is being cut through.