Journal of Hydrodynamics

, Volume 18, Issue 1, pp 281–284 | Cite as

A precision water-level and sediment-load monitoring system — An update

  • Hsien P. Pao
  • Sung C. Ling
Session A5


This paper presents an update of the basic design and performance of a precision pneumatic water-level gage that is suitable for application in most severe environments. The key to the success of this pneumatic bubbler gage is the incorporation of an analog “traveling-wave” low-pass filter which pre-filters out the noises generated by wind waves, swells and other short-period disturbances. It eliminates the high cost and error problems associated with a stilling well. The system satisfies the basic design requirement of ± 1mm resolution of water head. With multiple gages setup, the system can also be used to monitor the sediment load in rivers, estuaries and coastal waters.

Key words

pneumatic water-level gage low-pass pneumatic pre-filtering sediment load monitoring 


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  1. [1]
    Ling S.C. and Pao H.P. Precision water level and sediment load monitoring systems, 1 st International Symp. on Hydraulic Measurements, IAHR, Keynote paper, Nov. 1994, Beijing, China.Google Scholar
  2. [2]
    Schlichting, H. Boundary-layer Theory, McGraw-Hill, N.Y., 419–421.Google Scholar

Copyright information

© China Ship Scientific Research Center 2006

Authors and Affiliations

  1. 1.School of EngineeringThe Catholic University of AmericaWashington, D.C.USA

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