The Simrad PX Flow catch monitoring sensor monitors the speed of the water flow through your trawl. This allows you to make real-time decisions to maintain a correct towing speed.
Different species swim at different speeds. For an efficient fishery, it is important to know the trawl’s speed through water rather than the vessel’s speed. The flow through the trawl can be affected by many factors like the tide, currents, towing up or downhill, or even by the physical properties of the net itself. When you know the water speed (flow) in the trawl opening or the tunnel in real time, you can increase or decrease the vessel speed to adjust to the target species.
The Simrad PX Flow sensor is a wireless multifunction catch monitoring sensor that measures the speed of the water entering the trawl opening or inside the trawl. Unlike other water speed sensors, the PX Flow sensor makes this measurement with the small built-in acoustic Doppler current profiler (ADCP).
Using the Doppler principle is a huge benefit because it enables you to measure the speed of water at a distance from the net. This is particularly important if you want to measure inside a trawl where you have a boundary layer with much less water speed close to the net than in the centre of the tunnel.
The Simrad PX Flow is provided in different versions:
The version is defined by the type of sensor lid. The standard version of the sensor has a neutral lid.
The specific measurements a sensor can make depend on its lid type, its physical location on the gear, and on the type of receiver you use. The Flow sensor can make the following measurements:
By default, a PX Flow sensor can always make four measurements. An additional license is required if you wish to make more than the default number of measurements. All catch sensors with a software version higher than 2 can make up to eight measurements. This includes PX Flow. Remote functions are not considered as a measurement.
To receive the information from the sensor you need a suitable receiver (SR type), one or more hydrophones, as well as a computer running the Simrad TV80 program.
You can use all our PI Hydrophones. You can even use non-Simrad types, provided that the communication frequency match.