UniData Communication Systems Starflow QSD Manual page 25

Manual – Starflow QSD Model 6527B and 6537A
All 6527B and 6537A Starflow QSD's are supplied with pressure sensors and the diagram above
highlights the setting associated with this.
NOTE:
The 6527B and 6537A Starflow QSDs employ an absolute pressure sensor. Because of the way the
absolute presure sensor operates there is a need for a barometric sensor to compensate for changes
in barometric pressure. If there was no compensation then the depth sensor would give inaccurate
depth readings.
It is important the barometric sensor is placed in line with the instrument cable and needs to be
housed in a dry location such as equipment box. This equipment box must also be vented to
atmousphere to maintain a equal pressure between the inside and outside of the enclosure.
The settings above reflect some of the options associated the the pressure depth sensor.
Zero Result On Failure - If this check box is ticked then the instrument will return a zero pressure
depth if it becomes faulty. If this check box remains unchecked then the QSD will default to ultrasonic
depth readings and use these readings instead.
Enable Barometric Ref - If this check box is ticked the barometric Compensation is enabled. If it is
unticked the QSD will Return absolute pressure.
Show –Ve depth - There may be certain circumstances where the pressure sensor will detect a –Ve
pressure. When this check box Is ticked the QSD instrument will record a –Ve depth.Offset (mm).
Sometimes there is drift in the pressure redings and this needs to be zeroed. The best way to achieve
this is to remove the instrument from the water and click the button. This will zero the pressure depth
Readings. The offset value is then Displayed.
Unidata Manual - 6527B and 6537A Starflow QSD User Manual 17 01 2020.docx Page 23