Panasonic PT-DZ12000U Operating Instructions Manual page 192

MDA when background and sample count
times are one minute and k is 1.645.
MDA when background count time is ten
minutes and sample count time is one
minute and k is 1.645.
For Poisson distributions the following logic applies.
P is the probability of getting count "n"
n
n -
P = e / n!
n
n = the hypothetical count
= true mean counts
If the true mean, , is 3, then there is a 5% probability that we will
get a zero count and a 95% probability that we will get greater than
zero counts. There is a 65% probability that we will get 3 or more
counts.
POISSON STATISTICS
181
3 + 4.65 R
Eff
3 + 3.45 R
B
Eff
B