The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 26, 1985
Filed:
Sep. 06, 1983
Leroy J Everett, Glen Ellyn, IL (US);
Stanley J DeFilippis, Woodridge, IL (US);
Packard Instrument Company, Inc., Downers Grove, IL (US);
Abstract
A method for ascertaining radiochemical homogeneity in a liquid scintillation sample reliably identifies inaccurate geometries is disclosed so that meaningful activity counts can be determined. The novel method involves measuring the activity level of a set of homogeneous quench standard to obtain quench indicating parameter, or the Spectral Index of the External standard (SIE). The endpoint of each standard sample is computed allowing the formation of a table so that a calibration curve for each radionuclide of interest can be computed. The activity level of the unknown sample is then measured and the SIE determined so that an endpoint can be calculated. Finally, the theoretical endpoint obtained from a calibration curve is compared to the computed endpoint; if the computed endpoint of the sample deviates by more than 4% for tritium and 5% for higher energy radionuclides from the theoretical endpoint, the sample is considered to be nonhomogeneous or heterogeneous. An external standard-type liquid scintillation counting system is disclosed which automatically determines sample homogeneity, and it includes a microprocessor in its control system. The steps of the present invention and incorporated into the programmed steps for the microprocessor such that nonhomogeneous or heterogeneous samples are automatically identified on the readout of the system for an investigator.