Multiple industries rely upon dissolved oxygen to keep biological organisms alive. In water treatment, aerobic bacteria are used to digest organic matter. Raw water is pumped into large aeration ponds where submersed dissolved oxygen sensors are used to control the flow rate of air injection into the liquid. Proper aeration not only keeps the bacteria healthy but also helps to control the expense of operating these air blower systems, which account for 40 to 60% of the electrical cost of the facility.
In fish farming, changes in oxygen levels can be caused by algae blooms, pollutants, and seasonal changes. Oxygen levels below 4 to 5 ppm can cause die-off and loss of the fish stock. Dissolved oxygen must be constantly monitored to ensure proper aquatic health and operational profitability.
In environmental monitoring, many applications exist for dissolved oxygen measurement. Large manufacturing sites for pulp and paper, steel production, and chemicals use large volumes of water in their production processes. These facilities have in-house water treatment operations to remove pollutants before the effluent water is pumped back into the local source. Government regulations mandate that the dissolved oxygen levels of the effluent must be sufficiently high to avoid harming the river or lake that receives this treated water.
In the applications described above, it is common to submerse the dissolved oxygen sensor beneath the surface. A long, fixed cable is used to send the sensor output signal to the dissolved oxygen transmitter or process control system.
VisiWater DO P Arc Sensor is designed for submersion with a 10-meter fixed cable.