Skip to Content
Find More Like This
Return to Search

Method and apparatus for measuring butterfat and protein content using microwave absorption techniques

United States Patent

November 14, 2000
View the Complete Patent at the US Patent & Trademark Office
Idaho National Laboratory - Visit the Technology Transfer and Commercialization Office Website
A self calibrating method and apparatus for measuring butterfat and protein content based on measuring the microwave absorption of a sample of milk at several microwave frequencies. A microwave energy source injects microwave energy into the resonant cavity for absorption and reflection by the sample undergoing evaluation. A sample tube is centrally located in the resonant cavity passing therethrough and exposing the sample to the microwave energy. A portion of the energy is absorbed by the sample while another portion of the microwave energy is reflected back to an evaluation device such as a network analyzer. The frequency at which the reflected radiation is at a minimum within the cavity is combined with the scatter coefficient S.sub.11 as well as a phase change to calculate the butterfat content in the sample. The protein located within the sample may also be calculated in a likewise manner using the frequency, S.sub.11 and phase variables. A differential technique using a second resonant cavity containing a reference standard as a sample will normalize the measurements from the unknown sample and thus be self-calibrating. A shuttered mechanism will switch the microwave excitation between the unknown and the reference cavities. An integrated apparatus for measuring the butterfat content in milk using microwave absorption techniques is also presented.
Fryer; Michael O. (Roberts, ID), Hills; Andrea J. (Iowa City, IA), Morrison; John L. (Idaho Falls, ID)
Bechtel BWXT Idaho, LLC (Idaho Falls, ID)
09/ 058,265
April 10, 1998
CONTRACTUAL ORIGIN OF THE INVENTION The United States has rights in this invention pursuant to Contract No. DE-AC07-94ID13223 between the U.S. Department of Energy and Lockheed Martin Idaho Technologies Company.