Photoelectric sensor is a sensor that works on the principle like a transistor as a switch. This sensor works as a result of the activity or movement of a light. Light energy will be converted into electrical signals.There are 3 types of photoelectric sensors namely: Via Beam Transmitter and Receiver are placed separately and separately. The sensor when enumerating sunlight by an object between the transmitter and receiver so that the light receiver is lost at any time. This type of photoelectric has the longest distance than other types. Retro reflector Transmitter and receiver are placed together and require a reflector for operation. The object is detected because it cuts the light between the sensor and the reflector so that the receiver does not receive light. This photo cell allows further remote sensing. With the presence of a reflector the emitted light will be reflected charged to the receiver. Blend in The transmitter and receiver are placed together and use the light reflected directly from the object for detection. The choice of photosensor for this type must consider the object's surface type (rough, smooth, blurry, bright). With an opaque surface, the distance sensing will be highly visible to the object's color. Light colors affect the maximum sensing distance and dark colors affect the minimum sensing distance.