6537A Starflow QSD

The Unidata 6537 Starflow QSD SDI12 and Modbus Instrument is used to measure water velocity, depth, temperature and conductivity of water flowing in rivers, streams, open channels and large pipes. When used with a companion Unidata IP data logger, flow rate and total flow can also be calculated. 

The 6537 Instrument is robust, reliable and easy to use. It is completely sealed against water ingress, low maintenance, low power, no calibration and no fussy power arrangements required. 

Ultrasonic Doppler Principle in Quadrature Sampling Mode is utilised to measure water velocity. The 6537 Instrument transmits ultrasonic energy through its epoxy casing into the water. Suspended sediment particles, or small gas bubbles in the water reflect some of the transmitted ultrasonic energy back to the 6537 Instrument’s ultrasonic receiver instrument that processes this received signal and calculates the water velocity. 

The 6537 Starflow QSD incorporates ultrasonic depth sensor and an absolute pressure depth sensor. An ultrasonic depth sensor measures 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. 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 6537 Starflow QSD should be connected to the 6515 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 depth measurement.

 The 6537 Instrument has a 4 electrode electro conductivity instrument (EC) included to measure the quality of the water. 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 on conductivity is a strong indicator of a pollution event.

The 6537 instrument’s low profile form factor minimises disturbance tothe flow it’s measuring. Furthermore, 6537 instrument measures velocityin both directions and is suitable for use in wide range of water qualities,from sewage to potable water, sea water too.

With a companion Unidata data logger or a telemetered Neon Remote Loggerthe instrument can be programmed to compute flow rate and total flow inpipes and open channels of known dimensions.