|The detection limit, LD, answers the
"If you were to measure a sample, what would the count rate
have to be for, say, 95% certainty of detection?"
A distribution of counts, were we to measure the sample a large
number of times, would have a standard deviation of sD.
We need to be certain, to a degree determined by kb,
that the chance of not detecting the activity when it is really
there is only b, i.e.
= LC + kbsD
When ka and
kb correspond to the 95% confidence