Standard Practice for Calibrating a Fathometer Using a Bar Check Method

Importancia y uso:

4.1 The accuracy of depth measurements made by a fathometer or echo sounder requires a number of corrections because of the variability of sound or acoustic velocity in water with changes in temperature, salinity, and depth of water. In addition instability of the equipment can also result in significant errors. For additional information see Practice D5073.

4.2 Calibration of echo sounding instruments is absolutely critical in assuring the adequacy of depth measurements. When an echo sounder has been accurately calibrated, any observed (recorded) depth can be related to the true depth of water. Since the intended purpose of echo sounding is to measure the “true” depth, an independent “true” reference must be used.

4.3 A bar-check is the most wide-spread, easiest to construct, and most economical mechanical method to determine corrections for instrument and velocity errors.

4.4 This procedure explains the calibration of a fathometer or electronic depth sounder using a bar-check.

4.5 Bar-checking techniques and equipment are general in nature and may need to be modified for use in specific field conditions.

Subcomité:

D19.07

Volúmen:

11.01

Palabras clave:

bathymetric surveys; depth sounding; echo sounders; fathometers; hydrography; reservoir surveys; sediment surveys; velocity profiler;