Chemetrics - K-7540 - Colormetric Test Kit Dissolved Oxygen Chemets 0-40 Part Per Billion Chemetrics 30 Pkg Qty, Ea

ITEM #: 1888902
The level of dissolved o x ygen in natural waters is often a direct indication of quality, since aquatic plants produce o x ygen, while microorganisms generally consume it as they feed on pollutants. At low temperatures the solubility of o x ygen is increased; during summer, saturation levels can be as low as 4 ppm. Dissolved o x ygen (D.O.) is essential for the support of fish and other aquatic life and aids in the natural decomposition of organic matter. Waste treatment plants that employ aerobic digestion must maintain a level of at least 2 ppm dissolved o x ygen.
At elevated temperatures, o x ygen is highly corrosive to metals, causing pitting in ferrous systems such as high-pressure boilers and deep well oil recovery equipment. To prevent costly corrosion damage, the liquids in contact with the metal surfaces must be treated, usually by a combination of physical and chemical means. Deaeration can reduce the dissolved o x ygen concentration of boiler feedwater from several ppm to a few ppb. Chemical reducing agents such as hydrazine, DEHA, or sodium sulfite, may be used instead of or in conjunction with deaeration.
The Indigo Carmine Method
References: ASTM D 888-87, Dissolved O x ygen in Water, Test Method A. Gilbert, T. W., Behymer, T. D., Castañeda, H. B., "Determination of Dissolved O x ygen in Natural and Wastewaters, " American Laboratory, March 1982, pp. 119-134.
Test kits for environmental and drinking water applications (ppm range) employ the indigo carmine method. The reduced form of indigo carmine reacts with D.O. to form a blue product. The indigo carmine methodology is not subject to interferences from temperature, salinity, or dissolved gases such as sulfide, which plague users of D.O. meters. Results are e x pressed as ppm (mg/L) O 2 .
The Rhodazine D Method
References: Developed by CHEMetrics ASTM Power Plant Manual, 1st. ed. p. 169 (1984). ASTM D 5543-15, Low Level Dissolved O x ygen in Water. Department of the Navy, Final Report of NAVSECPHILADIV Project A - 1598, Evaluation of CHEMetrics Feedwater Dissolved O x ygen Test Kit (1975).
C-7511: O x ygen, dissolved Comparator
Range: 0-20 ppb
Increments: 0, 2, 4, 6, 8, 12, 16, 20 ppb
Test kits for boiler waters and applications requiring trace levels of D.O. (ppb range) employ the Rhodazine D methodology. Developed by CHEMetrics, Inc., and approved by ASTM as the reference method for ppb D.O. determination, the Rhodazine D compound in reduced form reacts with dissolved o x ygen to form a bright pink reaction product. The method is not subject to salinity or dissolved gas interferences. O x idizing agents, including benzoquinone, can cause high results. Reducing agents such as hydrazine and sulfite do not interfere. Results are e x pressed as ppm (mg/L) or ppb (ug/L) O 2 .
Low-range dissolved o x ygen test kits include a special sampling tube for use with boiler feedwater. This device allows the user to break the tip of the ampoule in a flowing sample stream in order to preclude error from contamination by atmospheric o x ygen.
WARNING! This product can e x pose you to chemicals including methanol, which is known to the State of California to cause birth defects or other reproductive harm. For more information go to
Dissolved Oxygen CHEMets Kit, Rhodazine D Method, Range: 0-40 ppb
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