Panasonic PT-DZ12000U

COUNTING STATISTICS
B S+B S+B B
Minimum Detectable Activity k + 2k%R x t x (1+t /t )
2
S+B
(MDA) MDA = t x Eff
Minimum Detectable Count Rate
D B S+B S+B B
LLD = L = MDCR k + 2k%R x t x (1+t /t )
2
S+B
t
C B S+B B B
L = k x %R x t + R x t
k = 1.645 (for 95% Confidence Level)
S+B
t = sample count time
B
t = background count time
B
R = background count rate
Eff = efficiency of the detector (expressed as a decimal)
S+B
R = sample count rate
LLD is Lower Limit of Detection
D
L is the Decision Level
C
L is the Critical Level and generally expressed as counts (or
signal level) above background
K 0.674 1 1.645 1.96 2.58 3.00
% C.L. 50 68.3 90 95 99 99.7
B
If R is in DPM it must be converted to CPM before using the
above equations.
A ‘k’ of 1.645 is used as the 95% confidence level for a two-
tailed distribution.
Gaussian statistics should be used for > 30 counts and Poisson
statistics for < 30 counts. The typical formulas such as those
above are an attempt to blend the two statistical models.
COUNTING STATISTICS
B S+B S+B B
Minimum Detectable Activity k + 2k%R x t x (1+t /t )
2
S+B
(MDA) MDA = t x Eff
Minimum Detectable Count Rate
D B S+B S+B B
LLD = L = MDCR k + 2k%R x t x (1+t /t )
2
S+B
t
C B S+B B B
L = k x %R x t + R x t
k = 1.645 (for 95% Confidence Level)
S+B
t = sample count time
B
t = background count time
B
R = background count rate
Eff = efficiency of the detector (expressed as a decimal)
S+B
R = sample count rate
LLD is Lower Limit of Detection
D
L is the Decision Level
C
L is the Critical Level and generally expressed as counts (or
signal level) above background
K 0.674 1 1.645 1.96 2.58 3.00
% C.L. 50 68.3 90 95 99 99.7
B
If R is in DPM it must be converted to CPM before using the
above equations.
A ‘k’ of 1.645 is used as the 95% confidence level for a two-
tailed distribution.
Gaussian statistics should be used for > 30 counts and Poisson
statistics for < 30 counts. The typical formulas such as those
above are an attempt to blend the two statistical models.
COUNTING STATISTICS
B S+B S+B B
Minimum Detectable Activity k + 2k%R x t x (1+t /t )
2
S+B
(MDA) MDA = t x Eff
Minimum Detectable Count Rate
D B S+B S+B B
LLD = L = MDCR k + 2k%R x t x (1+t /t )
2
S+B
t
C B S+B B B
L = k x %R x t + R x t
k = 1.645 (for 95% Confidence Level)
S+B
t = sample count time
B
t = background count time
B
R = background count rate
Eff = efficiency of the detector (expressed as a decimal)
S+B
R = sample count rate
LLD is Lower Limit of Detection
D
L is the Decision Level
C
L is the Critical Level and generally expressed as counts (or
signal level) above background
K 0.674 1 1.645 1.96 2.58 3.00
% C.L. 50 68.3 90 95 99 99.7
B
If R is in DPM it must be converted to CPM before using the
above equations.
A ‘k’ of 1.645 is used as the 95% confidence level for a two-
tailed distribution.
Gaussian statistics should be used for > 30 counts and Poisson
statistics for < 30 counts. The typical formulas such as those
above are an attempt to blend the two statistical models.
COUNTING STATISTICS
B S+B S+B B
Minimum Detectable Activity k + 2k%R x t x (1+t /t )
2
S+B
(MDA) MDA = t x Eff
Minimum Detectable Count Rate
D B S+B S+B B
LLD = L = MDCR k + 2k%R x t x (1+t /t )
2
S+B
t
C B S+B B B
L = k x %R x t + R x t
k = 1.645 (for 95% Confidence Level)
S+B
t = sample count time
B
t = background count time
B
R = background count rate
Eff = efficiency of the detector (expressed as a decimal)
S+B
R = sample count rate
LLD is Lower Limit of Detection
D
L is the Decision Level
C
L is the Critical Level and generally expressed as counts (or
signal level) above background
K 0.674 1 1.645 1.96 2.58 3.00
% C.L. 50 68.3 90 95 99 99.7
B
If R is in DPM it must be converted to CPM before using the
above equations.
A ‘k’ of 1.645 is used as the 95% confidence level for a two-
tailed distribution.
Gaussian statistics should be used for > 30 counts and Poisson
statistics for < 30 counts. The typical formulas such as those
above are an attempt to blend the two statistical models.