The HOA1884 series Transmissive Sensor consists of an infrared emitting diode facing an NPN silicon phototransistor or photodarlington encased in a black thermoplastic housing. Detector switching takes place whenever an opaque object passes through the slot between emitter and detector. The side mounting package is useful in applications in which the interruptive element is parallel to the mounting plane. Both emitter and detector have a 0.02-inch (0.508mm) x 0.04-inch (1.02mm) vertical aperture. The HOA1884 series employs plastic molded components. Housing material is polyester. Housings are soluble in chlorinated hydrocarbons and ketones. Recommended cleaning agents are methanol and isopropanol.