10 Calculation Methods 10-5
Figure 10-7 Calculation Process
AD Value
Absorbance
QC Result
Calibration Parameter
Response
Test Result
QC Conclusion
10.2.1 Calculating Absorbance
The system measures the light intensity through photoelectric conversion, linear
amplification and AD conversion. For the light intensity signal
i
I
of Channel i, the AD
output
i
D
is:
iadapei
IKKKD â‹…â‹…â‹…=
Where,
pe
K
- photoelectric conversion factor
a
K
- linear amplification factor
ad
K
- AD conversion factor
i
D
- test data of Channel i
i
I
- light intensity of Channel i
So,
i
i
i
i
i
D
D
I
I
A
00
lglg ==
Where,
i
A
- absorbance of Channel I,
0i
D
- background AD output,
i
D
- AD output after the substrate is added.
In theory, when the lights are off, the AD output of each channel will be zero. In practice,
because of the existence of dark current, there is still a background output
dibackgroun
D
,
which should be deducted. Then, the complete absorbance formula should be: