Patent ID: 6756571
Filing Date: 2004-06-29
Classification: F02D,G01F,G01N

Abstract:
A system for compensation of contamination of a heated element in a heated element gas flow sensor, said heated element becoming heated from an ambient temperature to an elevated temperature upon application of electrical power to the heated element during a startup time period, said system comprising:a processing circuit having an input and an output, a voltage signal from the heated element being connected to said processing circuit input, means in said processing circuit which reads a plurality of temporally spaced signals as data from said processing circuit input during the startup time period, means in said processing circuit which computes parameters of a transfer function corresponding to said data, means in said processing circuit which calculates a contamination correction factor as a function of at least one parameter of said transfer function, said processing circuit utilizing said correction factor to modify a measured gas flow rate by the gas flow meter after the heated element attains the elevated temperature to compensate for contamination of the heated element.