摘要 |
The present invention computes the uncertainty in the calibration factor or efficiency of a radiation sensor for that portion of the uncertainty arising from imprecise knowledge of the exact measurement conditions. This is accomplished in one aspect of the invention, by accurately defining a mathematical model of the sensor, the sample, and other items affecting the efficiency; then defining the default or expected or normal dimensions or values of each of the parameters in the mathematical model; then defining which of the values or parameters in the mathematical model are variables; for each variable parameter defining the range of variation and the shape of the distribution of those variable parameters; randomly selecting a value for each of the variable parameters in the model, using distribution shape and limits to create a mathematical model of one possible variation of source-detector measurement configuration; using this mathematical model and dimensions to compute the efficiency of the defined source-detector measurement configuration; repeating this random selection process a large number of times; and then computing the mean and standard deviation describing the uncertainty in that efficiency. In a further aspect of the invention, all of the preceding is done while using the mathematical model to compute the efficiency for each of a several energies, in order to evaluate the efficiency versus energy response of the measurement apparatus, and the uncertainty versus energy response of the apparatus.
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