Explanation of the criteria for classification and numbering of components      C71.3.10
   (JUN 00)
Explanation of the dates on the component's description



1.   Purpose and objectives

     To measure water level without contacting water's surface.

2.   Description

     The Acoustic Water Level Gauge is a device for continuous measurement of water level for rivers and dams. As the gauge utilises a transmitter-receiver that operates on an ultrasonic wave reflection method, it can measure water level without actually coming into contact with the water. 
Consequently, the gauge does not require underwater structures, such as measuring wells and posts, so installation can be completed at low cost. Moreover, measurements can be carried out at sites where there is high water and rapid currents, where the river bed changes frequently, and where 
the current is harsh as a result of pebbles, debris, and other objects in the water.

     A pole or beam is needed to install the gauge.

     The accuracy is within 1cm and the range is 13.5m.

3.   Input

     Actual water level.

4.   Output

        Water level on a digital data display, as a digital signal (B.C.D.) or an analogue signal (0V-5V DC and 4mA-20mA DC).

5.   Operational requirements and restrictions

     The transmitter-receiver should be at 1.5m from the surface when the water is at its highest possible level and at a maximum of 15m when water level is at its lowest possible. Avoid exposed objects near the beam that might give spurious reflections.

6.   Form of presentation

     A catalogue and instrument specifications are available.

7.   Operational experience

     About 120 sets were installed in Japan in 1999.

8.   Originator and technical support

     Yokogawa Denshikiki Co.,Ltd.

9.   Availability

     From the HOMS National Reference Centre for Japan.

10.  Conditions on use

     Hardware is for sale.


(First entered: 01 FEB 93

Last updated: 21 APR 00)