Patent ID: 7348783
Filing Date: 2008-03-25
Classification: G01N

Abstract:
1. A multi-functional pH meter, comprising: a sensor unit comprising a substrate, an indium tin oxide film on said substrate, a sensing film on said indium tin oxide film and connecting to a conductive wire, an electrode, and a package material covering said sensing film, said indium tin oxide film, and a portion of said substrate and exposing the sensing film via a sensing window; an analog signal processing unit for processing analog signals from said sensing unit via said conductive wire; a microprocessor unit for receiving the signals from said analog signal processing unit and generating a pH value of a solution being detected; a liquid crystal display unit for displaying the pH value; a compact flash card unit for storing the pH value; a data transmission unit for transmitting the pH value to a computer via Universal Serial Bus (USB) and Universal Asynchronous Receiver/Transmitter (UART) interfaces; an amplifier used as a front-end processing circuit for a sensing signal to increase the signal-to-noise ratio of said sensing signal; a low pass filter for filtering low frequency noises and suppressing the interference of the 60 Hz AC mains frequency to said sensing signal; and a level adjusting circuit for adjusting the potential level of the processed sensing signal to fit the input range and specification of a analog/digital converter.