Applications:

    Ultrasonic Sensors are frequently used in:

• Water level measurement with the sensor attached to a bridge or structure directly over the water.
• For flood applications to avoid damage from debris flow

Advantages of ultra sonic sensors for water level measurement:

• Non-contact sensor allows for easy installation on a bridge or structure over the water.
• Non-contact sensor reduces the problem of sensor fouling or corrosion. Also potential damage from debris is reduced.

Limitations of ultra sonic sensors for water level measurement:

• The speed of sound through air varies with the air’s temperature. The transducer may contain a temperature sensor to compensate for changes in operating temperature. However, this only takes into account the temperature at the sensor, which may be different as the sound wave approaches the water
• Debris, extreme turbulence or wave action of the water can cause fluctuating readings. Use of a damping adjustment in the instrument or a response delay may help overcome this problem.
• Maximum distance to the water level surface is typically 30 feet or less.
• Limited usage in shallow streams or in streams with very high velocities with minimum depth requirements.
• Very high concentrations of fine sediment in suspension can scatter and absorb the sonic pulse, preventing reflection of a detectable echo.
• Ultrasonics typically require more power than other water level sensors.
• Build-up on the sensor head, even simple condensation, can cause problems with the sensors operation.