Ph-Value With Liquid Reagent - Lovibond MiniDirect Mode D'emploi

Methods
GB
0.0.0
Zero
Test
PH
RESULT
Notes:
1 . When testing chlorinated water the residual chlorine contents can influence the colour
reaction of the liquid reagent . This can be avoided (without interfering with the pH
measurement) by adding a small crystal of Sodiumthiosulfate (Na
sample before adding the PHENOL RED solution . PHENOL RED tablets already contain
Thiosulfate .
2 . Due to differing drop size results can show a discrepancy in accuracy by comparison with
tablets . This can be minimised by using a pipette (0 .18 ml PHENOL RED solution is
equivalent to 6 drops) .
3 . After use replace the bottle cap securely .
4 . Store the reagent in a cool, dry place ideally between 6 °C and 10°C.
28

pH-value with liquid reagent

6.5 – 8.4
Fill a clean vial (24 mm Ø) with 10 ml of the water sample and
perform zero calibration (see "Operation") .
Fill the vial with drops of the same size by holding the bottle vertically
and squeeze slowly:
6 drops of PHENOL RED solution .
Close the vial tightly with the cap and invert several times to mix the
contents .
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: ± 0,2 pH
S O · 5 H O) to the
2 2 3 2
MiniDirect_ClpH_1 09/2008
marks