Patent ID: 7207208
Filing Date: 2007-04-24
Classification: G01B,G02B

Abstract:
1. A method of determining a length L 1 at least representative of the length of a tube that defines a passage in an optical fibre cable along which an optical fibre unit can be installed by blowing, said method comprising the steps of providing a first volume V 1 containing a gas at a first pressure P 1 , releasing said gas into a second volume V 2 that comprises a tube that defines a passage in an optical fibre cable, determining a second gas pressure P 2 in said second volume V 2 after release of said gas from said first volume, determining said second volume V 2 by reference to said first pressure P 1 , said second pressure P 2 and said first volume V 1 and determining said length L 1 by reference to said second volume V 2 .