Manual – Starflow QSD Model 6527B and 6537A
Unidata Manual - 6527B and 6537A Starflow QSD User Manual 17 01 2020.docx
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3.6
Accelerometer
The Starflow QSD has an integral accelerometer sensor to measure the inclination of the instrument.
The sensor returns the roll and pitch angle of the sensor (in degrees). This information can be useful
in ensuring the installation position of the sensor is correct and for determining if the instrument has
moved (bumped or washed away) during post installation inspection.
3.7
Power Supply Voltage
The instruments internal power supply voltage is readable as a measurement parameter. The
operating range of the power supply is 12 to 24V DC. If the supply voltage falls below defined limits
the instrument stop taking measurements to ensure only quality data is measured.
3.8
Signal Spread
This can be used to determine the amount of “turbulence” affecting the signal quality and used to
reject the measurement if the spread (turbulence) is too great. A good flow would return a spread
value of around 50, anything above 100 would be considered poor.
10
Excellent SPREAD
20
Very good SPREAD
30
Good SPREAD in dirty river water
40
Good SPREAD in clean river water (Typical)
60
Average SPREAD
80
Poor SPREAD
90
Bad SPREAD (Poor site selection)
100
Above 100 gives unreliable velocity data.
3.9
Received Signal Strength Indicator (RSSI)
The RSSI channel is the measurement of the received signal power. RSSI values may change
significantly each measurement because of the number of reflectors in the water at that time
RSSI Channel Interpretation
0
Threshold signal at Analog.Gain=5 (default)
1
Useable Signals
5
Good signal
10
20
Typical signal in clean river water
40
1000 Saturated signal
Therefore in very laminar flow situations (perfect conditions) the RSSI value should be very low,
between 1-10. In typical river situations RSSI will be between the 1 and 30
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