Method for evaluating sample activities in a multidetector liquid scintillation counter
AssigneeWallace Oy
InventorsTapio Yrjonen, Heikki Kouru
Life of this patent
Estimating the term…
Abstract
A method for the evaluation of sample activities in multidetector liquid scintillation counters. All prepared quench curve standards are measured only in one reference detector in order to establish the relationship between the quench levels and the counting efficiencies. In addition, only two of the standards, preferably those with lowest and highest level of quench, are measured in every detector in order to establish the relationship of the quench levels between the reference detector and any other detector and in order to establish the relationship of the counting efficiencies between the reference detector and any other detector. The activities of unknown samples are evaluated by utilizing the predetermined relationships.
Claims4
A method for evaluating the activity of an unknown sample in a multidetector liquid scintillation counter, said method comprising the steps of:
- (1) storing in a memory of a multidetector liquid scintillation counter:
- (a) a relationship between quench level and counting efficiency for a first reference detector;
- (b) a relationship between quench levels of said reference detector and a measuring detector for each measuring detector of said multidetector counter;
- and
- (c) a relationship between counting efficiencies of said reference detector and a measuring detector for each measuring detector of said multidetector counter;
- (2) measuring a quench level and a count rate of the unknown sample with a measuring detector of said multidetector counter;
- (3) converting the quench level of the unknown sample measured in (2) to the corresponding quench level for said reference detector using the relationship between quench levels of said reference detector and said measuring detector stored in (1) (b);
- (4) determining the counting efficiency of said reference detector corresponding to the quench level of said reference detector determined in (3) using the relationship between quench level and counting efficiency of said reference detector stored in (1)(a);
- (5) converting the counting efficiency of said reference detector determined in (4) to the corresponding counting efficiency of the measuring detector used in (2) using the relationship between the counting efficiencies of said reference detector and said measuring detector stored in (1)(c);
- and
- (6) dividing the count rate of the unknown sample measured in (2) by the counting efficiency of said measuring detector determined in (5) to obtain the activity of the unknown sample.
Dependencies are inferred from the claim text.