Hanna-instruments HI 84500 Manual do Utilizador descarregar pdf (Página 19)

Pump calibration must be performed every time the syringe, pump tube, the titrant bottle or the ORP

electrode is changed. A pump calibration is recommended before each set of titrations or after the

titrator is left idle for several hours.

• Press MENU, select Setup and select the corresponding range according to the table below:

• Ensure the pump is primed with the correct titrant for the selected range (HI 84500-50 Low

Range Titrant or HI 84500-51 High Range Titrant).

Sample preparation: Use a clean pipette to precisely add the appropriate amount of

HI 84500-55 Calibration Standard to a clean beaker as indicated below:

PUMP CALIBRATION PROCEDURE

egnaRwoL egnaRhgiH

mpp0.04ot0.1 mpp004ot03

Low Range (Free & Total SO

) - 1 mL

High Range (Free & Total SO

) - 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.

• Fill the 20 mL beaker up to the 5 mL mark with the HI 84500-60

Acid Reagent and add the contents to the 100 mL beaker.

• Add the contents of one packet of HI 84500-62 Stabilizer

Packet to the sample beaker.

• Press CAL key.

ELECTRODE CHECK PROCEDURE

Before taking any measurements with the HI 84500 minititrator, it is recommended to check

the HI 3148B ORP electrode using the following steps:

• Press Meter to enter mV mode.

• Pour roughly 15 mL of HI 7021 into a 20 mL beaker. This does not need to be exact, as

long as the PTFE junction is covered by the solution.

• Place the electrode in the solution, stir gently for a few seconds and verify the mV reading.

If the mV reading is 240 ± 20 mV this indicates the electrode is in good condition and can

be used for titrations. A mV reading of 240 ± 30 mV indicates the electrode is beginning

to drift. Follow the “Electrode Conditioning and Maintenance”, Probe Maintenance section

on page 32. If the mV reading is greater than 240 ± 40 mV replace the electrode.

• Remove the electrode from the solution and rinse thoroughly with deionized or distilled water.

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.

1 2 ... 14 15 16 17 18 19 20 21 22 23 24 ... 35 36

Sem comentários

Hanna-instruments HI 84500 Manual do Utilizador Página 19