pH measuring – a different way!

Hanna Instruments is proud to present a new way of measuring pH! The HI-779 is a checker photometer with which you can quickly, easily, and moreover, accurately measure pH in swimming water according to the recognised phenol red method. The checker does not have to be calibrated with buffers, as with a tester, and there is also no electrode to be stored in storage solution.

Designed to accurately determine pH levels in pool water using normal disinfectants or salt water chlorination by electrolysis, each HI-779 is delivered in a case with custom insert and is supplied with:

• Swimming pool pH reagent starter kit
• 1.5V AAA Alkaline battery (1 pc.)
• Instruction manual

This checker is designed as a more accurate alternative to chemical test kits.

HI-779 features a single-button operation system and is easy to use. The large LCD is easy to read and the auto shut-off feature assures the battery will not be drained.

How to operate your Checker

Press the ON/OFF button to turn the checker on. All segments will be displayed for a few seconds, followed by “Add”, “C.1” with “Press” blinking.

• Fill the cuvette with 10 mL of unreacted sample and replace the cap. Insert the cuvette into the checker and close the cap.
• Press the ON/OFF button. When the display shows “Add”, “C.2” with “Press” blinking, the checker is zeroed.
• Remove the cuvette. Unscrew the cap and add 5 drops of HI-779-25 pH reagent indicator. Replace the cap and invert 5 times to mix.
• Insert the cuvette into the checker and close the cap. Press the ON/OFF button. The instrument displays the result in pH. The checker automatically turns off 10 minutes after reading.

Interferences

Interference may be caused by:

Magnesium Hardness above 700 mg/L as CaCO₃ (when Calcium Hardness is more than 1000 mg/L as CaCO₃).

Bromine above 4 mg/L as Br2 (when Calcium Hardness is more than 800 mg/L as CaCO₃).

Tips for an Accurate Measurement

1. Ensure the sample does not contain any debris.
2. When the cuvette is placed into the checker, it must be dry outside and free of fingerprints, oil and dirt.
3. Wipe the cuvette thoroughly with HI-731318 microfiber cleaning cloth or a lint-free cloth prior to insertion.
4. Shaking the cuvette can generate bubbles, causing higher readings. To obtain accurate measurements, remove such bubbles by swirling or by gently tapping the cuvette.
5. Do not let the reacted sample stand too long after reagent has been added, as accuracy will be affected.
6. Discard the sample immediately after the reading has been taken or the glass might become permanently stained.