Dynamically Calculated Refractive Index for Determining the Thickness of Roofing Materials

摘要

Disclosed is a system for measuring and controlling the thickness of asphalt roofing materials during manufacturing. Light beams are used to generate a time of flight signal that is used to determine the thickness of the asphalt roofing layer. A controller generates a thickness control signal that controls a coater to modify parameters of the coater to produce the asphalt roofing layer with a desired thickness.

主权项

1. A method of controlling the thickness of an asphalt roofing layer during manufacturing comprising:
measuring temperature and density of said asphalt roofing layer; determining a refractive index for said asphalt roofing layer, that varies with density and temperature of said asphalt roofing layer, using empirical data; measuring time of flight of a light beam through said asphalt roofing layer; calculating said thickness of said asphalt roofing layer by multiplying said time of flight by speed of light divided by said refractive index to obtain a measured thickness; comparing said measured thickness of said asphalt roofing layer with a desired thickness to generate an error signal; using said error signal to generate a control signal in a controller; using said control signal to control said measured thickness of said asphalt roofing layer during manufacture of said asphalt roofing layer.