Patent ID: 8538717

Claim:
A method for absorbance correction in a spectroscopic heating value sensor comprising the steps of: passing radiation from a radiation source having at least one absorbing wavelength for a radiation absorbing sample fluid through a non-radiation absorbing fluid and measuring an intensity of said radiation after passing through said nonradiation absorbing fluid, producing an initial reference radiation intensity value; passing said radiation through said radiation absorbing sample fluid and measuring said intensity of said radiation after passing through said radiation absorbing sample fluid, producing a sample fluid radiation intensity value; passing said radiation through said radiation absorbing sample fluid and measuring said intensity at a non-absorbing wavelength of said radiation for said radiation absorbing sample fluid after passing through said radiation absorbing sample fluid, producing a correction reference radiation intensity value; determining a measured radiation absorbance of said radiation absorbing sample fluid using said initial reference radiation intensity value and said sample fluid radiation intensity value; determining a radiation absorbance adjustment value using said initial reference radiation intensity value and said correction reference radiation intensity value; and determining an absorbance difference between said measured radiation absorbance and said radiation absorbance adjustment value, producing a true radiation absorbance for said radiation absorbing sample fluid at said at least one radiation absorbing wavelength.