optical sensor 101 in some embodiments the bores 850 of the rods 830 a and 830 b can be aligned a collection of fasteners not shown can be passed through the bores 850 and adjustably tensioned to pre tension the optical sensor 101 instead of or in addition to use of the outer rods 810 a 810 b fig1 is an exploded perspective view of another example optical sensor mounting system 1000 fig1 and 12 are side and top views of the optical sensor mounting system 1000 fig1 15 are various cross sectional side views of the optical sensor mounting system 1000 with reference to fig1 15 the optical sensor mounting system 1000 removably attaches an optical sensor loop not shown such as the example optical sensor loop 200 of fig2 to the pipe 102 the optical sensor mounting system 1000 includes a support wedge 1010 having a bottom face 1012 a side face 1014 a a side face 1014 b and a groove 1016 the bottom face 1012 is formed with a concave angular or curved profile that approximates the outer diameter of the pipe 102 the side faces 1014 a 1014 b are substantially planar faces that intersect the bottom face 1012 at angles approximately tangent to the outer diameter of the pipe 102 and approach but do not intersect each other at the groove 1016 the optical sensor mounting system 1000 includes.