38477BA2B
7 – 710 25.5.09
6 Explanations Volume 7
Figure 6-10 Calibration curve
All count rates for each calibration point are automatically adjusted
using the following formula.
cps
new
= (cps
old
- Bq) * (cps 0%
new
- Bg) / (cps 0%
old
- Bg) +
Bg
cps
new
: new calculated pulse rate
cps 0%
new
: new pulse rate at 0%
cps 0%
old
: old pulse rate at 0%
cps
old
: old count rate
Bg
: Background
Example from the table at 70% cps 0%
new
: 5000 cps
cps 0%
new
: 7000 cps
cps
old
(70%): 3000cps
Bg: 100cps
cps
new
= (3000-100) * (5000-100)/(7000-100) + 100 = 2159 cps
Level in % Pulse rate in cps
0 5000
40 3580
70 2159
100 171
CPS
Level
b
e
f
o
r
e
a
d
j
u
s
t
m
e
n
t
a
f
t
e
r
a
d
j
u
s
t
m
e
n
t