With continuous row of sensors, Dynamic Optical Window counts small parts ejected from injection molding machines, as well as plastic capsules and scrap air-conveyed in transparent tube or dropped from chute. User can preset minimum target size for triggering, enabling window to recognize only whole parts. Signal duration is adjustable across 10-300 msec range. Signal response time is 200 µsec. Three models offer detection areas of 1.5 x 3.1, 3.1 x 3.1, and 4.7 x 3.1 in.