Electro-Chemical Devices (ECD) CA6 Hardness Analyzer - Manual (Page 79)

Linearity Test
ppm Absorbance
0 0.038
250 0.0724
500 0.147
1000 0.3070
R² = 0.9994
-0.05
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0 200 400 600 800 1000 1200
Absorbance
68