Patent ID: 6834552
Filing Date: 2004-12-28
Classification: G01D,G01L,G02B

Abstract:
A fibre-optical strain-gauge for a construction whose strain is to be measured across first and second construction surfaces thereof, comprising:first and second optical fibres; and a strain-gauge body including first and second body surfaces which are located opposite to one another, first and second symmetrically disposed fibre-holding elements in which respective said first and second optical fibres are secured, first and second mounting elements for mounting the strain-gauge body to the respective first and second construction surfaces of the construction whose strain is to be measured, first and second double hinges which respectively connect said first and second fibre-holding elements to respective said first and second mounting elements, (a) said first double hinges having (i) a proximal first hinge thereof which is positioned close to the first fibre-holding elements and which is positioned close to the first body surface of the strain-gauge, and (ii) a distal first hinge thereof which is positioned distant from the first fibre-holding element and which is positioned at a distance from said first body surface, and (b) said second double hinges for the second fibre-holding element having (i) a proximal second hinges thereof which is positioned close to the second fibre-holding element and which is positioned close to the second body surface, and (ii) a distal hinges thereof which is positioned distant from the second fibre-holding element and which is positioned at a distance from said second body surface, whereby the first and second fibre-holding elements move in opposite directions perpendicular to an axial direction of the fibres when the mounting elements move towards or away from each other.