Manual – Starflow QSD Model 6527B and 6537A
Unidata Manual - 6527B and 6537A Starflow QSD User Manual 17 01 2020.docx
Page 5
3.0
OPERATING PRINCIPLES & MEASURED PARAMETERS
The 6527B and 6537A Starflow QSD measure:
•
Flow velocity
•
Depth (ultrasonic)
•
Temperature
•
Depth (Pressure)
•
Electrical Conductivity (EC) – 6537A Only
•
Tilt ( the angular orientation of the instrument)
The Starflow QSD performs data processing and analysis each time a measurement is made.
This can include rolling averaging and outlier/filter functions for Depth (ultrasonic), Velocity, Depth
(Pressure) and Conductivity (6537A). The function parameters can be configured via SDI-12
eXtended command or Sonic software.
3.1
Flow Velocity Measurement
For Velocity the Starflow QSD uses Continuous Mode Doppler. To detect water velocity, an
ultrasonic signal is transmitted into the water flow and echoes (reflections) returned from particles
suspended in the water flow are received and analysed to extract the Doppler shift (velocity). The
transmission is continuous and simultaneous with the returned signal reception.
During a measurement cycle the Starflow QSD emits a continuous signal and measures signals
returning from scatterers anywhere and everywhere along the beam. These are resolved to a
mean velocity that can be related to a channel flow velocity at suitable sites.
The receiver in the instrument detects reflected signals and those signals are analysed using
digital signal processing techniques.
Internally the instrument auto scales over these ranges if the range is manually set in the
settings: Bidirectional velocity capability is a supported option.
20mm / s to 0.8 m sec
20mm / s to 1.6m/s (default)
20mm / s to 3.2 m/s
20mm / s to 13.2 m/s
