The invention relates to a method and arrangement for measuring optical properties from paper or board that constitutes a target to be measured and comprises two planar surfaces. The invention also features water dispersible pharmaceutical dosage forms including cefdinir as active agent and methods for preparing the dosages. The application of heat assists in the expression of obstructions or occlusions in the meibomian glands to restore sufficient sebum flow to the lipid layer to treat dry eye. The second differential output unit receives NRZ input signals and an inverted clock signal, and generates differential RZ-mode outputs. The tumbler holds the auxiliary key in a manner irremovable from the key cylinder in accordance with the rotational position of the rotor.