Hanna Instruments HI931, Руководство пользователя, Страница: 12 / 218

8
QUICK ST
ART GUIDE
• Use the or to select pH 4.01 buffer solution.
• Use the second beaker of pH 4.01 buffer solution to rinse the pH electrode, temperature probe and propeller stirrer.
• Immerse the pH electrode, temperature probe and propeller stirrer in the pH 4.01 buffer solution. The pH electrode’s bulb must
be completely immersed in the buffer solution and the reference junction needs to be 5-6 mm below the surface. Add additional
buffer if necessary.
• Press to turn on the propeller stirrer.
• Once the reading has stabilized, press
to update the calibration.
• Repeat this procedure for pH 7.01 and 10.01 buffer solutions.
• Press
to accept and exit pH calibration mode.
HOW TO PERFORM A TITRATION
Required Solutions
• Titrant - 500 mL of 0.1 M (mol/L) Sodium Hydroxide (NaOH) in a titrant bottle.
• Sample - 0.1 mol/L Hydrochloric Acid (HCl).
• Distilled or deionized water.
Note: Analytical grade reagents and water should be used for accurate results.
Priming the Burette
• Insert the aspiration tube in the titrant bottle and the dispensing tube in a waste beaker.
• From the main screen press
.
•Highlight the
Prime Burette
option and then press .
•Enter the number of burette rinses. At least 3 rinses are recommended.
•Press
to start.
•The message “Executing...” will be displayed.
Note: Make sure you have continuous liquid flow inside the burette. For accurate results, the aspiration tube, the dispensing tube
and the syringe must be free of air bubbles.
Method Selection
For this analysis, we will use the
HI1009 Neutralization w/ NaOH
.
To select this method:
• Press
. Use the and keys to highlight
HI1009 Neutralization w/ NaOH
.
• Press .
Setting Method Parameters
To display the method parameters, press .
The View/Modify Method screen will be displayed.
Only certain parameters can be changed.
For this titration, the NaOH titrant concentration and the size of the HCl sample need to be entered.
To accomplish this:
• Highlight
Titrant Conc . option, then press .
The Titrant Concentration screen will be displayed.
• Enter the correct value, then press .
• Highlight Analyte Size option, then press .
• Enter the volume of the sample (e.g.: 5 mL), then press .
• Press , highlight Save Method option and then press .