Place your samplers so that they are in the shade between 11 a.m. and 4 p.m. Keep them away from sediment. Pads should be kept off the bottom, either with a special sampler or by suspending them in the water column. Keep them away from iron. Iron in the water or in bacteria can coat the pads, preventing OB adsorption and emission.
Turbulence can cause the pad fibers to break down.
Avoid highly colored waters. Waters with tannins and lignins contain naturally fluorescing materials. Avoid waters with lots of coarse organic matter. As leaves break down, they form naturally fluorescing compounds. Find the right exposure time.