Tintometer Lovibond MD 110 Mode D'emploi page 44

Methods
GB
PH
0.0.0
Zero
Test
PH
RESULT
Notes:
1. For photometric determination of pH-values only use PHENOL RED tablets in black
printed foil pack and marked with PHOTOMETER.
2. Water samples with low values of Alkalinity-m (below 35 mg/l CaCO
pH readings.
3. pH-values below 6.5 and above 8.4 can produce results inside the measuring range.
A plausibility test (pH-meter) is recommended.
4. Salt error
For salt concentrations below 2 g/l no significant error, due to the salt concentration of
the reagent tablet, is expected. For higher salt concentrations the measurement values
have to be adjusted as follows:
Salt content
Correction
according to Kolthoff (1922)
1)
according to Parson und Douglas (1926)
2)
Reagent
PHENOL RED PHOTOMETER
44
pH-value with Tablet
6.5 – 8.4
Fill a clean vial (24 mm Ø) with 10 ml of the water sample and
perform zero calibration (see "Operation").
Add one PHENOL RED PHOTOMETER tablet straight from the foil to
the 10 ml water sample and crush the tablet using a clean stirring rod.
Close the vial tightly with the cap and swirl gently several times until
the tablet is dissolved.
Place the vial in the sample chamber making sure that the
are aligned.
Press the [ZERO/TEST] key.
The method symbol flashes for approx. 3 seconds.
The result is shown in the display as pH-value.
Tolerance: ± 0.1 pH
30 g/l (seawater)
- 0,15
1)
Form of reagent/Quantity
Tablet / 100
) may give wrong
3
60 g/l 120 g/l
- 0,21 - 0,26
2) 2)
Order-No.
511770BT
MD110_2 03/2018
marks
180 g/l
- 0,29
2)