Lovibond Maxi Direct, Instruction Manual, Page: 19 / 268

17
MaxiDirect_2c 03/2010
CaCO
3
°dH
°eH
°fH
°aH
5. By determining Alkalinity-p and Alkalinity-m it is possible to classify the alkalinity as
Hydroxide, Carbonate and Hydrogencarbonate.
The following differentiation is only valid if:
a) no other alkalis are present and
b) Hydroxide und Hydrogen are not present in the same water sample.
If condition b) is not fulfilled please get additional information from ”Deutsche
Einheitsverfahren zur Wasser-, Abwasser- und Schlammuntersuchung, D 8”.
Case 1: Alkalinity-p = 0
Hydrogen carbonate = m
Carbonate = 0
Hydroxide = 0
Case 2: Alkalinity-p > 0 and Alkalinity-m > 2p
Hydrogen carbonate = m – 2p
Carbonate = 2p
Hydroxide = 0
Case 3: Alkalinity-p > 0 and Alkalinity-m < 2p
Hydrogen carbonate = 0
Carbonate = 2m – 2p
Hydroxide = 2p – m
1.1 Methods
Notes
1. The terms Alkalinity-p, p-Value and Alkalinity to pH 8.2 are identical.
2. For accurate test results exactly 10 ml of water sample must be taken for the test.
3. This method was developed from a volumetric procedure for the determination of
Alkalinity-p. Due to undefined conditions, the deviations from the standardised method
may be greater.
4. Conversion table:
mg/l CaCO
3
°dH °fH °eH
1 mg/l CaCO
3
---- 0.056 0.10 0.07
1 °dH 17.8 ---- 1.78 1.25
1 °fH 10.0 0.56 ---- 0.70
1 °eH 14.3 0.80 1.43 ----