PCR

PLS

RMSEC [mg/l]

176

122

RMSECV [mg/l]

276

280

R² (calibration)

0.50

0.76

R² (cross validation)

0.13

0.19

Cumulative variance by component #

PCR

PLS

Spectral

COD

Spectral

COD

1

96.24

15.80

96.18

16.55

2

99.05

26.38

98.97

30.63

3

99.70

33.68

99.67

38.50

4

99.86

37.12

99.83

46.10

5

99.96

43.78

99.94

50.23

6

99.97

44.68

99.97

66.17

7

99.98

49.60

99.98

75.83