Sensor Configuration

Abstract

A sensing means comprises four uniaxial sensors each capable of detecting a movement component along a respective axis having a respective orientation and arranged such that the angles between any two of said respective orientations of said respective axes are substantially equal, wherein the uniaxial sensors are arranged such that in use the respective axes are at substantially the same angle to the vertical.

1 . A sensing means comprising four uniaxial sensors each capable of detecting a movement component along a respective axis having a respective orientation and arranged such that the angles between any two of said respective orientations of said respective axes are substantially equal, wherein the uniaxial sensors are arranged such that in use the respective axes are at substantially the same angle to the vertical.  
   
   
       2 . A vibration sensing means for determining vibration components in three orthogonal directions comprising four uniaxial sensors each capable of detecting a vibration component along a respective axis having a respective orientation and arranged in a configuration such that the angles between any two of said respective orientations of said respective axes are substantially equal, wherein the uniaxial sensors are arranged such that in use the respective axes are at substantially the same angle to the vertical.  
   
   
       3 . A sensing means according to either of claims  1  and  2 , wherein each respective axis is at substantially 54.74° to the vertical.  
   
   
       4 . A sensing means according to any preceding claim, wherein the uniaxial sensors have associated directional vectors orientated along the respective axes, the direction of the vectors determined by the polarities of the respective uniaxial sensors.  
   
   
       5 . A sensing means according to  claim 4 , wherein the polarities of the uniaxial sensors are arranged such that the directional vectors of all of the uniaxial sensors have positive components in the vertical direction.  
   
   
       6 . A sensing means according to any of  claims 1  to  4 , wherein the polarities of the uniaxial sensors are arranged such that the directional vectors of all of the uniaxial sensors have negative components in the vertical direction.  
   
   
       7 . A sensing means according to any preceding claim, wherein the uniaxial sensors are located along a common axis.  
   
   
       8 . A sensing means according to  claim 7  wherein in use the common axis is in the vertical direction.  
   
   
       9 . A sensing means according to any preceding claim, wherein the uniaxial sensors comprise geophones.  
   
   
       10 . A sensing means according to any of  claims 1  to  8 , wherein the uniaxial sensors comprise seismometers.  
   
   
       11 . A sensing means according to any of  claims 1  to  8 , wherein the uniaxial sensors comprise accelerometers.  
   
   
       12 . A sensing means according to any preceding claim for use in a borehole.  
   
   
       13 . A sensing means as herein described with reference to the accompanying drawings.