Method and apparatus for measuring coating thicknesses on continuously moving material

Apparatus for measuring coating thickness on strip material moving along a predetermined path, said apparatus comprising:

• a. a shuttle carrying a measuring probe having coating thickness sensing means;
• b. drive means for reciprocating said shuttle along a preselected segment of the path travelled by the strip material;
• c. means for selectively engaging and disengaging said shuttle and the moving strip, said shuttle being pulled by the strip for synchronous movement therewith during engagement thereof and being driven independently of the strip during disengagement thereof;
• d. said drive means moving said shuttle forwardly along said path at a spaced slightly slower than that of the moving strip prior to engagement therewith to accomplish a smooth engagement of said shuttle with the moving strip;
• and
• e. means for operatively coupling and uncoupling said probe and the moving strip while said shuttle and the strip are engaged.

The method of measuring coating thickness on continuously moving strip material using beta radiation techniques which comprises:

• a. reciprocating a shuttle carrying a measuring probe having a radioactive isotope source and a radiation detection device along a preselected segment of the path travelled by the moving strip material;
• b. selectively engaging and disengaging the shuttle and the moving strip with the shuttle being pulled by the strip for synchronous movement therewith during engagement thereof and being driven independently of the strip during disengagement thereof;
• c. moving the shuttle forwardly along the path prior to engagement with the moving strip material to accomplish a smooth engagement therewith;
• and
• d. selectively engaging and disengaging the probe with and from the moving strip while the shuttle and the strip are engaged.