Berthold LB 134 - 11.2 Calibration Factors for LB 1231 and LB 1233

LB 134 9. Basis of Calculation
118
Definition of statistical errors:
Formula
abs. error
rel. error
Gross count rate
1
*)1(*


bb
RWRWR
12 

c
b
b
T
R
R
b
b
R
R
Net count rate
)(
0
RRR
bn

22
0 bn
RRR 
or
12
0
0


c
b
n
T
R
T
R
R
n
n
R
R
Basis of Calculation Ratemeter:
Designation
Variable
Unit
Default
Parameters
Averaging
(preset: time, accuracy)
Time
Time constant (preset time)
c
T
[s]
120
Accuracy (preset accuracy)
P
[%]
3.0
Sigma factor
S
4.0
Nuclide (with calibration factor K)
K
Net
Preset time constant:
t
W
1

for
c
Tt 
c
T
W
1

for
c
Tt 
Preset accuracy:
t
W
1

for
100/P
R
R
b
b


c
T
W
1

for
100/P
R
R
b
b


Reset and recalculate of
W
,
t
and
b
R
if
bb
RSRR *
9.3 Search Mode
In the Search mode, the same computational algorithms are
used as in the Ratemeter mode to calculate the mean values.
The preset reject criterion is 5 . The time constant for the av-
eraging is 20 s. As a result, the display reacts much faster to
changes in the count rate than in the ratemeter mode.