Dissolved oxygen (DO) sensors perform liquid process measurement for determining the amount of oxygen dissolved or carried in the process liquid. There are three common technologies for dissolved oxygen measurements: polarographic, galvanic and optical. The standard units of measure are milligrams per liter (mg/l), parts per million (ppm), parts per billion (ppb), or % saturation. Various installation options including floating ball, retractable, flow thru, immersion, and direct insertion.
Measuring Sensor DO30G
The DO30G sensor for dissolved oxygen is designed for use in water treatment plants such as sewage treatment works, effluent activated sludge process, and potable water treatment. It is also effective in river monitoring, intake protection, fish farming, and other fields where water quality is important.
- OXYFERM with rugged membrane design
- Stable, fast response, low flow dependence
- Withstands numerous sterilizations
Sensors for ppb Applications
Dissolved oxygen measurements in the parts per billion range are critical in, but not limited to power generating plants. Maintaining a low level of dissolved oxygen in boiler feedwater assures that corrosion of certain components is minimized. A reliable measurement of ppb dissolved oxygen helps to reduce downtime and improve efficiency.
Optical Dissolved Oxygen Sensor, Hamilton VisiFerm
Hamilton's VisiFerm is the first optical sensor ever for the measurement of dissolved oxygen that has significant advantages compared to classical Clark cells because there's no electrolyte needed and the luminophore is embedded in a robust sensor cap. Typical applications are biotechnology, water treatment and monitoring as well as in breweries, wineries and soft drink processing.
Low ppb Optical Dissolved Oxygen Sensor, Hamilton VisiTrace
- VisiTrace optical DO sensor
- Optical oxygen sensor meets power plant, food/beverage industry needs
- Controlling dissolved oxygen to low ppb levels
- Maintaining product quality or reducing downtime
Dissolved Oxygen Sensor Applications
Water treatment dissolved oxygen monitoring equipment like the DO30G:
- Sewage treatment
- Effluent activated sludge process
- Potable water
- River monitoring
- Intake protection
- Fish farming
- Pharmaceutical applications
- Chemical plants
Parts per billion dissolved oxygen measuring instruments like OXYGOLD G/B:
- Electrolysis plants
Optical DO Sensors like VisiFerm:
- Chemical industry
- Air surveillance
- Fish farming
- Water management
- Gas and liquid phase sewage water
Low PPB Optical DO Sensors like VisiTrace:
- Power plant
- Low-downtime product quality maintenance
Dissolved Oxygen Sensor Working Principle
Membrane electrode dissolved oxygen measurement (galvanic cell, polarographic):
Without interference from the pH, oxidation, reduction substances, or turbidity of the water, this method measures a reduction or diffusion current created by dissolved oxygen concentration or oxygen partial pressure. An air layer forms on the membrane of the sensor in the water, and the oxygen concentration of that layer is in equilibrium with the water's dissolved oxygen concentration.
Optical measurement of dissolved oxygen process:
The optical oxygen sensor probes a cell culture container and uses fluorescent dye and a fiber optic reader to display a liquid's luminescence in the presence of oxygen. Higher oxygen levels yield lower emission intensities, so the DO can be measured via the luminescence peak, decay rate, or the signal phase difference.
When used to measure the dissolved oxygen in an aeration tank, sensors tend to quickly become contaminated and need frequent cleaning.
Removal of free oil and grease from a wastewater stream reduces the potential for equipment problems downstream. Three forms of oil are encountered in wastewater treatment at a refinery: Free Oil, Emulsified Oil, Dissolved Oil.
Having too much oxygen in the process is not a problem for the biological system; however the cost for generating the oxygen is one of the largest expenses. By obtaining a good representative average of the dissolved oxygen present in the basin could save the plant large amounts of money. For this reason multiple measurements points are sometimes put into place.
The detectors used to perform dissolved oxygen (DO) measurement in oxidation ditch type sewage treatment plants tend to become dirty quickly and require frequent cleaning.
- WTB10-DO1,-DO2,-DO3,-DO4 Terminal Box (687 KB)
- DO71 and DO72 fitting adapter assembly (676 KB)
- Model DO71 Optical Dissolved Oxygen Sensor (2.0 MB)
- Model DO72 Optical Dissolved Oxygen Sensor (2.3 MB)
- Model PR10 Manual Retractable Fitting (1.7 MB)
- 243560 VisiTrace 120mm (1.1 MB)
- Model DO71 and DO72 Optical dissolved oxygen sensors (1.1 MB)
- 243561 VisiTrace 225mm (1.1 MB)
- K9088PE (DO30G Polishing Powder) - Aluminum oxide Powder (106 KB)
- 237139 Oxylyte G (189 KB)
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