In-Situ® RDO® Optical Dissolved Oxygen Technology Outperforms Traditional Methods

Three methods are generally used tomeasure dissolved oxygen (DO) in surface waters:Winkler titration, membrane-covered electrochemical sensors (polarographic or galvanic cell), and luminescent-based sensors. Optical (luminescent) technology formeasuring DO levels in water has quickly become a wellaccepted method due tomany advantages over membrane-based sensors, and its close correlation to Winkler titrations. Laboratory, process, and long-term field applications can all benefit from the optical DO method, which offers improved accuracy and reduces operating costs.

On November 3, 2009, the U.S. Environmental Protection Agency (EPA) granted nationwide approval to three In-Situ RDO optical DO methods under the Alternate Test Procedure (ATP) process. These methods can be used in the measurement of Biochemical Oxygen Demand (BOD), Carbonaceous Biochemical Oxygen Demand (CBOD), and Dissolved Oxygen (DO) under the CleanWater Act (CWA). The complete and accurate names of themethods are:

• In-Situ Inc. Method 1003-8-2009 Biochemical Oxygen Demand (BOD) Measurement by Optical Probe (ATP Case No. N09-0020)
• In-Situ Inc. Method 1004-8-2009 Carbonaceous Biochemical Oxygen Demand (CBOD) Measurement by Optical Probe (ATP Case No. N09-0021)
• In-Situ Inc. Method 1002-8-2009 Dissolved Oxygen Measurement by Optical Probe (ATP Case No. N05-0014)