Method and apparatus for determining urea concentration
AssigneeToyo Engineering Corporation
InventorsYoshihiro Tajiri, Takuya Hayabuchi, Naohiro Teramoto, Yasuhiko Kojima, Eiji Sakata, Haruyuki Morikawa
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Abstract
A method for determining a urea concentration in an aqueous solution containing urea, includes: hydrolyzing the urea in the aqueous solution, measuring an electric conductivity χ of the aqueous solution, and determining the urea concentration in the aqueous solution from the electric conductivity χ using a correlation between the urea concentration and an electric conductivity.
Claims10
A method for determining an original urea concentration in an aqueous solution containing urea, comprising:
- hydrolyzing the urea in the aqueous solution to a level of 1 ppm or less at a temperature between about 170° C. to about 300° C. and at a pressure at which the aqueous solution is not boiled;
- measuring an electric conductivity χ of the aqueous solution after hydrolysis;
- and determining the original urea concentration in the aqueous solution from the electric conductivity χ using a correlation between the urea concentration and the electric conductivity.
A method for determining an original urea concentration in an aqueous solution containing urea and one or more substances influencing the electric conductivity of said solution, comprising:
- measuring an electric conductivity χ′ in the aqueous solution;
- hydrolyzing the urea in the aqueous solution to a level of 1 ppm or less at a temperature between about 170° C. to about 300° C. and at a pressure at which the aqueous solution is not boiled;
- measuring an electric conductivity χ in the hydrolyzed aqueous solution;
- and
- determining the original urea concentration in the aqueous solution from a difference between the electric conductivities χ and χ′ using a correlation between the urea concentration and the electric conductivity.
Dependencies are inferred from the claim text.