EKF Diagnostics Hemo Control - Page 37

Theoretical Principles
User Manual Hemo Control
34
34
P
0
P
b
absorbierende Lösung
der Konzentration c
P
0
P
b
absorbing solution
with concentration c
source side
detector side
Figure 25 – Principle of photometric measurement
P
0
: 100 % - light intensity,
P: remaining light intensity,
b: distance through the solution
P
P
A
0
log
Equation 1 – Absorbance A
bcA  
Equation 2 - Lambert-Beers Law
 : molar extinction coefficient
b: distance through solution in the microcuvette
c: concentration of solution
Using Lambert-Beers Law, (refer to Equation 2) the concentration of the
hemoglobin in the microcuvette can be determined. To this end the
equations are solved for the concentration c.
P
P
Kc
0
log
where
 b
k
K 
Equation 3 - Calculation of concentration
k: proportionality factor for measurement method correction
(taking into account design conditions)