An apparatus and method of analyzing an aqueous solution, as may be implemented with a hand-held portable electronic device (10). A test pad (32) responsive in color to a characteristic of an aqueous solution is interrogated by the device by measuring, in a plurality of wavelength ranges, intensity values...http://www.google.de/patents/US20070287182?utm_source=gb-gplus-sharePatent US20070287182 - METHOD AND APPARATUS FOR ANALYZING SOLUTIONS
