The model SM906 series is a selfcontained, pulse-echo device that both transmits and receives sonic energy within the specified analog span. Operating on 15 to 24 VDC, these sensors use the latest ultrasonic sensing and microprocessor technology that allows the sensor to ignore all surrounding sonic interference and detect only the designated object. During operation, the sensor monitors the distance to an object or level while generating a proportional analog output relative to the two analog span limits. When an object is within the analog span, the analog output value changes proportionally in relation to the analog span limits. For example, if the object is halfway between the analog span limits, the output is either 5 V or 12 mA, depending on the output model selected. The output range adjusts to the size of the analog span and remains proportional regardless of where the limits are set for the analog span. The sensors are equipped with a multicolor sensing status LED and a amber output LED. The multicolor LED indicates where the level or target position is relative to the span limits. It is green when the object is between the analog span limits, red if closer than the near span limit, and amber if farther than the far span limit. The amber 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 amber LED.