The 6527B Starflow QSD incorporates an ultrasonic depth sensor and an absolute pressure depth sensor. An ultrasonic depth sensor measures the water depth using the ultrasonic principle and has a range of up to 5m. An absolute pressure sensor measures pressure forces applied to the strain gauge. The absolute, non-vented, sensor reports a value equal to the sum of the water pressure and the atmospheric pressure above the water. In order to compensate for the atmospheric (barometric) pressure fluctuation, the 6527B Starflow QSD should be connected to the 6515D Starflow QSD barometric reference. The absolute pressure sensor has a range of up to 10m. Having sensors using different depth measurement methods provides flexibility in in-depth measurement.

The 6527B sensor’s low profile form factor minimises disturbance to the flow it’s measuring. Furthermore, the 6527B instrument measures velocity in both directions and is suitable for use in a wide range of water qualities, from sewage to potable water, and seawater too. With a companion Unidata telemetered Neon Remote Logger, NRL,  the sensor can be programmed to compute flow rate and total flow in pipes and open channels of known dimensions.

The Unidata 6527B Starflow QSD can be upgraded to include a data logger 6527B-L, similar in function to the older Starflow 6526 products. Using Starlog V4 software and the built-in logger, cross-section profiles can be defined to calculate flow rate and total flow.

The Unidata 6537A Starflow QSD SDI-12 and Modbus sensor includes a 4-electrode electroconductivity sensor (EC) for measuring water quality. Water quality is measured on an ongoing basis and this parameter can be recorded along with velocity and depth to better analyse the nature of the water in open channels and pipes. Conductivity is a very important water quality measure, and any spikes in conductivity are a strong indicator of a pollution event. The 6537A Starflow QSD can be upgraded to include a data logger 6537A-L as well. Using Starlog V4 software and the built-in logger, cross-section profiles can be defined to calculate flow rate and total flow.

The Unidata 6515D Barometric Reference is a module used with the Starflow QSD sensors and instruments to correct the pressure sensor depth sensor readings for atmospheric pressure variations.

The 6515D barometric reference is a module installed in line with a Starflow QSD sensor or instrument to monitor the barometric pressure at its geographical location. With this module, barometric compensation can be achieved for the depth sensor within the Starflow QSD sensor/instrument, allowing it to provide pressure and derived depth readings corrected for differences in atmospheric pressure. The 6515D barometric reference inbuilt electronic components communicate with the Starflow QSD sensor/instrument via a dedicated protocol, providing regular atmospheric pressure readings. These values are then applied to the pressure sensor, allowing the Starflow QSD Instrument to report true atmospheric pressure compensated depth readings.

An alternative to using a 6515D barometric reference can be any other electronic barometer, which is read and then the depth readings are corrected for atmospheric pressure in another system, such as another data logger or an RTU connected to the SCADA system.

An alternative to this barometric reference could be to consult the local weather service to obtain the current barometric pressure for the geographical location where the Starflow QSD sensor/instrument is deployed. These readings can then be used as a depth compensation factor in the end system, where the velocity and depth data are stored.

The Model 6705 expanding band kit allows you to install a Starflow QSD instrument in pipes of different sizes. The band is flexible enough to fit irregular shapes such as ovoid sections. All components are made from stainless steel and the band fittings are 100mm wide to match the 6527M mounting bracket.