Measurement of hot container wall thickness

A method of measuring thickness between surfaces of a hot-formed glass article that emits radiation, comprising the steps of:

• (a) measuring a first intensity of such radiation at a first wavelength at which the radiation is emitted from both surfaces of the article,
• (b) measuring a second intensity of such radiation at a second wavelength at which the radiation is emitted substantially entirely from only one surface of the article, and
• (c) determining thickness of the article between the surfaces as a combined function of said first and second intensities measures in said steps (a) and (b).

Apparatus for measuring wall thickness of molded hollow glass articles having interior and exterior wall surfaces while the articles are hot from the molding process, comprising:

• means for disposition exterior to the article to measure a first intensity of radiation emitted by the article at a first wavelength at which intensity varies as a function of both temperature at said surfaces and wall thickness between said surfaces,
• means for disposition exterior to the article to measure a second intensity of radiation emitted by the article at a second wavelength at which intensity varies as a function of temperature at said surface and independent of wall thickness between said surfaces, and
• means for determining wall thickness between said surfaces as a combined function of said first and said second intensities.

A method of measuring wall thickness of molded hollow glass articles having a predetermined average wall thickness, and while the articles are hot from the molding process, comprising the steps of:

• (a) measuring intensity of radiation emitted by the article indicative of surface temperature,
• (b) determining wall thickness of the article as a combined function of intensity measured in said step (a) and said predetermined average wall thickness.