Physical Oceanography, Vol. 16, No. 1, 2006
AUTOMATION OF RESEARCH IN SEAS AND OCEANS
METHODICAL AND ALGORITHMIC METROLOGICAL ASPECTS OF THE
DEVELOPMENT AND OPERATION OF HYDROSTATIC
V. I. Zaburdaev, P. V. Gaiskii, and A. N. Logvinchuk
By using the relationships between the measurement error of hydrostatic CTD sea-level meters,
the errors of measuring channels of hydrostatic pressure, temperature, and conductivity, and the
errors of determination of the gravitational acceleration, we estimate the admissible measurement
errors for separate channels. Simplified relations for the evaluation of salinity and density of wa-
ter corresponding to the class of accuracy of the level meter are presented. Possible differences
between the readings of the level meters mounted at coastal level-measuring posts and the actual
sea level in the coastal zone caused by the weak water exchange in the sea–well system are esti-
At present, due to the rapid progress in miniaturization and the level of integration of electronic radio com-
ponents and primary measuring pressure, temperature, and conductivity transducers (gauges) with high metro-
logical characteristics, the hydrostatic meters of the level of fluid are extensively used for the research purposes
and ecological monitoring, in the industry, private life, etc.
However, the commercial promotional information often does not contain (or contain incomplete) data on
the principles of operation of hydrostatic meters of the level of fluid and the metrological characteristics of the
entire device or its separate measuring channels. This creates certain difficulties in choosing proper level meters,
especially in the case of high requirements to the accuracy of measurements of the level.
In the present work, we study the principles of operation of hydrostatic CTD-meters of the level of fluid, es-
tablish the relationship between the admissible errors of measurement of the level and the errors of separate mea-
suring channels of the device, develop simplified algorithms of data processing, and analyze the causes of possi-
ble difference between the readings of coastal level meters and the actual sea level.
Principles of Operation of Hydrostatic Level Meters and the Basic Equation of Measurements
The relationship between the level of fluid
and hydrostatic pressure
of a column of fluid at the point
of location of a pressure meter can be derived from the following integral hydrostatic equation :
Marine Hydrophysical Institute, Ukrainian Academy of Sciences, Sevastopol.
Translated from Morskoi Gidrofizicheskii Zhurnal, No.
76, January–February, 2006. Original article submitted December
13, 2004; revision submitted February 17, 2005.
52 0928-5105/06/1601–0052 © 2006 Springer Science+Business Media, Inc.