The Virtu™ analog series is a self-contained, pulse echo, analog sensing device that both transmits and receives sonic energy within a 508 mm (20 in ) maximum sensing range. Operating on 15 to 24 VDC, and employing the latest piezoelectric and microprocessor technology, Virtu™ sensors detect only those designated objects within a set "window" and ignore all surrounding sonic interference. Prior to operation, a simple and easy "teach" function is used to set the sensing window limits through either a remote or inline cable pushbutton. A near and far limit for a desired sensing window can be set anywhere within the sensing range and may be set to either encompass the full sensing range or be as small as 6 mm (0.25 in ). The sensor is equipped with three LED's to show the sensing status. The amber LED is off when an object is within the sensing window. The amber LED is on when an object is being sensed within the range of the sensor. The orange LED indicates the relative value of the analog output and varies in intensity according to the output. The higher the current or voltage output, the brighter the orange LED.