filament possible since the long filament will give
the least pressure as it bends very easily. If the patient does not feel the filament, it is shortened in 0.5 cm steps until it is felt. There should be four to eight touches at each length. When at least 50% of the touches are felt the test is completed. The length of the filament is noted and using the conversion chart supplied with the instrument, the reading can be converted into mg./sq. mm.