Banner "923" series ULTRA-BEAMs are rugged, reliable ultrasonic proximity sensors with analog outputs. They are ideal for applications that require proximity mode distance sensing and a continuous linear analog output (voltage sourcing or current sinking) throughout an adjustable sensing range. Typical applications are fill level sensing, position sensing and guidance, web tensioning and positioning, size sorting of objects on production lin, and centering control. Banner ULTRA-BEAM analog outputs interface directly to ordinary voltmeter and millimeter, LED barographs, variable speed DC motor drives, microprocessors, and programmable controllers. Use of ultrasonic (sound waves, not light) enables Banner ULTRABEAMs to detect objects that are totally undetectable or only marginally detectable by photoelectric (light dependent) methods. ULTRABEAM ultrasonic sensors can reliably detect objects regardless of their color or transparency to light. Banner analog ULTRA-BEAMs can sense the presence of clear glass or film just as reliably as they can detect the presence of a solid metal object of the same profile. When one of ULTRA-BEAM's analog outputs is connected to an appropriate instrument (even an accurately calibrated DC voltmeter or mm will suffice) the distance from the sensor face to a surface perpendicular to the sensing axis can be read with accuracy. "923" series analog ULTRA-BEAMs have a sensing range of 20 in to 20 ft, with the response pattern shown in figure A. Easily-accessible 15- turn clutched potentiometer (NULL and SPAN adjustments, located on top of the unit) allow the limits to be shifted to create a "sensing window" of adjustable "depth" anywhere within the 20 in to 20 ft range (see figure B). The limits of the sensing window can easily be reset when sensing requirements change. The maximum depth of the adjustable sensing window is 18'4" the minimum depth is 12". Objects beyond the far end of the window are ignored. Objects within the beam pattern and between the sensor and the near end of the window, however, will block the ultrasonic beam and prevent operation. For proper operation, an average target object should present to the sensor a minimum of 1 square foot of reflective surface area for every 10 ft of sensing distance.