SonTek/YSI Argonaut-XR Technical Manual - HydroScientific West

SonTek/YSI
Water temperature (°C): (Enter value)
Temperature is required for calculating the speed of sound, which is used to convert Doppler
shift to water velocity. The entered temperature may or may not be used for sound speed
calculations depending upon the temperature mode setting (see below). The acceptable range of
values if from -5 to 50°C.
Water salinity (ppt): (Enter value)
Salinity is required for calculating the speed of sound, which is used to convert Doppler shift to
water velocity. The acceptable range of values if from 0 to 60 parts per thousand (ppt).
Speed of sound (m/s): (Derived value)
The speed of sound in water is given in the menu for information purposes only, and cannot be
directly changed by the user. The displayed value is computed from the user-supplied values of
temperature and salinity. If temperature mode is set to MEASURED, the sound speed used during
data collection will be based upon the value from the Argonaut temperature sensor. See the
Argonaut Principles of Operation for information on the effect of sound speed on Argonaut
velocity data.
Temperature mode: (Multiple-choice)
Temperature mode refers to the source of temperature data used for sound speed calculations.
USER indicates that the value input in the setup menu should be used; MEASURED indicates that
the value from the Argonaut temperature sensor should be used. The temperature sensor used by
the Argonaut is considered sufficiently reliable and accurate (± 0.1°C) for sound speed
calculations, thus MEASURED is the common choice. The USER setting is occasionally used to
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Figure 14 – ARGONAUT Setup Screen
Argonaut Software Manual (March 1, 2001)