Fast-Response Dissolved Oxygen (DO) Sensors Support Continuous Submerged Water Applications

Nov. 8, 2011 - PRLog -- The DO6400 and DO6441 Process Dissolved Oxygen Sensors from Sensorex are reliable, fast-response submersible galvanic sensors available with either a built-in 4-20mA output signal capability for direct connection to a PLC or they can be connected to a standard 4-20mA transmitter and local display.

The DO6400 and DO6441 Process Dissolved Oxygen Sensors are ideal for long term continuous deployment in wastewater and aquaculture applications.  Their galvanic sensor construction and electronics combine performance, ease of use and low maintenance to offer a reliable low life-cycle cost instrument for use in submerged water applications.

Dissolved oxygen (DO) sensors such as the Sensorex Models DO6400 and DO6441 monitor the amount of dissolved (free) oxygen present in water and wastewater. Wastewater treatment processes frequently utilize aerobic bacteria to break down organic compounds in sewage. If the amount of DO in wastewater becomes too low, the bacteria will die; wastewater treatment processes then stop operating efficiently and undesirable septic conditions occur.

Accurate DO measurement is also critical for aquaculture operations in order to ensure that the organisms being cultivated have access to the levels of oxygen necessary to maintain life. When DO levels are low, fish feeding is reduced and growth is suppressed. Very low levels of dissolved oxygen can lead to extreme stress on fish and even death.  

The low maintenance, dependable DO6400 and DO6441 Sensors feature reliable galvanic cell technology and a large volume electrolyte reservoir for long term continuous deployments. The easily replaceable membrane is available in either durable Teflon or wide span HDPE membrane for faster response. An optional integral temperature sensor is also available for both models.

The highly reliable DO6400 Dissolved Oxygen Sensor features a mV output (0.25-20
ppm) and the DO6441 Sensor offers a built-in 4-20mA output (0-100% and 0-200%).  The DO6400 Series Sensors are designed for easy installation and maintenance with a positive fit and easy-to-grip body design. They feature a Noryl body with silver cathode and operate at temperatures up to 50°C.

The Model DO6441T Sensor is perfect for aquaculture applications and now offers the user a factory calibrated 4-20mA output for direct PLC interface.   If an external transmitter with local display is desired, the DO6400 Series is compatible with the Sensorex DO500 and DOMA 4-20mA loop powered transmitters. The transmitter display can be programmed to read percent saturation, mg/mL or ppm DO. Temperature is also visible on the display via a Pt100 temperature sensor (automatic) or manual input.
   
There are two fundamental techniques for measuring DO—galvanic and polarographic. Both sensor technologies use an electrode system where the DO reacts with the cathode to produce a current.  Sensorex galvanic sensors in the DO6400 and DO6441 Series require no external voltage source, which is required with polarographic sensors, providing superior accuracy and lower maintenance for low life-cycle costs.

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Sensorex was founded in 1972 to manufacture quality sensors for water applications. The company today is a leader in sensor technologies and systems, manufacturing more than 2,000 different sensor packages. Our mission is to provide customers with quality pH, ORP, Conductivity, Dissolved Oxygen, Free Chlorine, Chlorine Dioxide and other specialty sensors as well as a full line of sensor accessories and knowledgeable customer service.