Eriometer

(ér-e-om'e-ter.) [From Gr. erion, fibre, and metron, measure.] (Opt.) An instrument proposed by Dr. Young for measuring the diameters of minute particles and fibres; it depends upon the diffractive fringes formed by the object to be measured. As these fringes increase with the size of the object, it is not difficult to form a scale of measurement based on this principle. [s. 339]