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14. PUMP CALIBRATION PROCEDURE
The calibration of the pump must be performed every time the syringe, pump tubing, the titrant bottle
or the pH electrode is changed. A pump calibration is recommended before each set of titrations, after
the titrator is left idle for several hours, or once daily.
Note:
A pump calibration needs to be done in the desired range and sample size. Pump calibration
is independent of the sample type.
• Press
MENU
, select
Setup
and select the corresponding range according to the table below:
Unit Low Range 20 or 50 High Range 20
%l.a.
0.01 to 0.20
0.1 to 2.0
°SH
0.4 to 8.9
4.4 to 88.9
°D
1.0 to 20.0
10 to 200
°TH
1.1 to 22.2
11.1 to 222.2
• Verify the electrode has been calibrated in 8.30 pH buffer.
• Ensure the pump is primed with the correct titrant for the selected range (
HI84529-50
Low Range
20 Titrant or
HI84529-52
Low Range 50 Titrant,
HI84529-51
High Range 20 Titrant).
Sample preparation:
Use a clean pipette, add a precisely measured amount of
HI84529-55
Calibration Standard to a clean beaker as indicated below:
Low Range 20 – 1 mL
Low Range 50 – 2 mL
High Range 20 – 10 mL
Note:
Failure to use a clean pipette will result in erroneous readings.
• Fill the beaker up to the 50 mL mark with the distilled or deionized water.
• Press
CAL
key. The instrument displays the date and time of the last electrode calibration, and the
last pump calibration for the selected range.
• Press
Pump
key.
Note:
Do not place the tip into the calibration beaker, place the tip over a waste beaker. A small
amount of titrant is dispensed when the pump resets.
50 mL
25 mL
15 mL
