This unweighted ends are attached to a common base plate. The reed and base plate assymbly is mounted in the field of an electromagnetic coil. This type of meter consists of a series of thin metal reeds of equal length usually of 4 mm wide and 0.5 mm thick. But slightly different weights are attached to one end of the reeds. This added weights made each reed mechanically resonant at a particular frequency. The weighted ends of the reeds are visible through a narrow window in the face of the meter housing and are painted white.