Ultrasonic Level Sensor Features
The WL750 ultrasonic level sensors are not susceptible to error due to the target material's color, shape or composition (e.g., transparent or opaque, liquid or solid).  The ultrasonic level sensors are particularly good for applications that must sense a non-metallic object in an environment where there is systematic, heavy wash down, liquid, dust, heavy spray, food, ink, or other environmental hazards.  Since the ultrasonic level sensor's sound energy is used for detection, the reflecting object does not have to be metal, but can also be glass, plastic or even paper.

Stagnant, non-agitated liquids and solids consisting of large and hard particles are good reflectors and, therefore, good candidates for ultrasonic level sensor measurement.  Fluff, foam and loose dirt are poor reflectors, and dust, mist or humidity in the vapor space tend to the absorb ultrasonic level sensor's pulse.  When these conditions are present, they are generally not measurableby ultrasonic level sensors.  As a rule of thumb, use 20% of the stated range of an ultrasonic level sensor to see if it will overcome these conditions.  Where these characteristics are present, a WL900 radar level sensor might be appropriate.

Architecture of Ultrasonic Level Sensors

Operation Principle of Ultrasonic Level Sensors

The WL750 ultrasonic level sensor's rmatched to air is stimulated by a pulse transmitter, and it generates a pressure wave that propagates to a target and then reflects (in similar fashion to a loudspeaker)  The reflected wave is received by the ultrasonic level sensor, in receiver mode, and is converted into an electrical signal (as a microphone would).  The ultrasonic level sensor's electrical signal is amplified and processed to find the reflected echo and then calculated to find the distance to a specific target.  The distance to an object is calculated and then converted by the ultrasonic radar level sensor to 4-20 mA signal.

Ultrasonic Level Sensor Still-Pipe Mounting Considerations

No end cut is required for pipes shorter than 6".  The ID of the pipe must be greater than the OD of the transducer nozzle.   If pipe is longer than 6", a 45° cut is required.