ADS Environmental Services IETG FlowHawk QR 775012 A4 - Manual (Page 51)

System Overview 2-15
Peak Combo Sensor
Ultrasonic Depth Sensor
To provide the depth of the flow, the sensor sends an ultrasonic
signal upward that bounces off the water surface – air interface.
The travel time from the sensor to the flow surface and back is
converted to distance, which translates into the depth of the flow.
Ultrasonic upward depth signals bouncing off water surface
Pressure Depth Sensor
A pressure transducer in the Peak Combo Sensor also measures the
depth of the flow over the sensor. The monitor can use this data for
comparison with other depth measurement devices in less than full-
pipe conditions. The pressure depth sensor also can measure depths