ADS Environmental Services Portable FlowShark Pulse QR 775006 A2 - Manual (Page 35)

2-14 ADS Portable FlowShark Pulse Manual
1 Sensor for Depth Measurement using Water-Ultrasonic (optional)
2 Sensor for Flow Velocity Measurement
3 Sensor Screw Joint (mobile)
4 Retaining Element
5 Sensor Body
6 Installation Help Screw M4
7 Cable Gland
8 Sensor Cable
Pipe Insertion Sensor
Flow Depth Measurement
Based on the sensor model, the water-ultrasonic velocity/combination sensor may
perform up to two types of depth measurement:
 Water-ultrasonic
 Hydrostatic fill level measurement
Water-Ultrasonic
Water-ultrasonic depth measurement involves using a horizontal sensor crystal to
determine flow depth based on the time difference between transmitting and receiving
a signal reflected off the flow surface (the transit-time method).
2
•
l
t c
h
l
=
Where,
h = Depth (i.e., fill) Level
c = Transit Time of Sound
t
1
= Time Elapsed Between the Transmitted and Received Signal
Sound travels in water at a speed of 4856 feet per second (1480 m/s) at 68 °F (20 °C),
varying at a rate of 0.13 % for each difference in degree Fahrenheit (0.23% for each