Patent ID: 6936158
Filing Date: 2005-08-30
Classification: G01B,G01N

Abstract:
1. An apparatus for measuring accumulated and instant rate of material loss or material gain and comprising: (a) a DC supply supplying said apparatus with power to perform measuring operations end said DC supply defining a positive DC voltage and a negative DC voltage; (b) a metal element defining a coated section having a first connector, a non-coated section having a second connector, and an interface having a third connector, said interface providing electrical and thermal connection between said coated section and said non-coated section experiencing corrosion or metal deposition in a measurement environment; (c) a first input power system generating a first system input signal and generating an interface input signal to said third connector of said metal clement; (d) a first power transmitter amplifier having a first power transmitter input receiving said first system input signal and having a first power transmitter output generating a first excitation output signal; (e) a first resistor for interconnecting said first power transmitter output and said first connector of said coated section of said metal element so as to constitute a first path of said first excitation output signal from said first power transmitter output through said first resistor and said coated section of said metal element to said third connector of said metal element, said first excitation output signal inducing a first metal element voltage across said coated section of aaid metal element; (e) a second resistor for interconnecting said first power transmitter output and said second connector of said non-coated section of said metal element so as to constitute a second path of said first excitation output signal from said first power transmitter output through said second resistor and said non-coated section or said metal element to said third connector of said metal element, said first excitation output signal further inducing a second metal element voltage across said non-coated section of said metal element; and (f) a first sensor amplifier having a first sensor amplifier input connected to said first connector of said coated section of said metal element, having a second sensor amplifier input connected to said second connector of said non-coated section of said metal element, and having a first sensor output generating a first sensor amplifier output signal constituted by an amplification of said first metal element voltage, said second metal element voltage and/or a voltage difference between said second metal element voltage and said first metal element voltage; said metal element defining a first resistance between said first connector of said coated section and said third connector of said metal element and a second resistance between said second connector of said non-coated section and said third connector of said metal element, wherein said second resistance increases as a function of corrosion and decreases as a function of metal deposition so as to induce said voltage difference between said second metal element voltage and said first metal element voltage.