FAQ - Frequently Asked Questions

For the internal reference solution for the pH electrode, use the internal reference solution 300 (3.33 mol/L-KCL solution)

 

NOTE:

• The internal reference solution may run short during continuous analysis.

  When the internal reference solution volume falls to the glass section as in the figure, replenish the internal reference solution to the specified level according to the instruction manual included with the pH electrode. While the amount of internal reference solution decrease fluctuates with delivery conditions and environmental temperature, generally the internal reference solution volume drops 0.1 to 1.0 mm per hour.

  
• Once the internal reference solution volume falls to the narrow glass section, replenishing the internal reference solution may cause bubbles to enter the glass electrode. As bubbles are extremely difficult to get rid of, be careful not to let the internal reference solution volume fall too low.
  If bubbles enter the electrode, gently shake the electrode to remove the bubbles. Be careful not to break the electrode when shaking it.
• Maintain the pH electrode performance by replacing the internal reference solution every one to two months. Remove the pH electrode according to "Replacing the pH Electrode", then replace the internal reference solution according to this section and the instruction manual included with the pH electrode.

  Click here for "(LC) Replacing the pH Electrode".

• Use internal reference solution whose shelf life has not expired.

 

HINT: Although there may be white crystals (KCL crystals) on the refilling port, they do not affect the performance.
  If crystals are on the refilling port, wipe it with paper wiper wet with purified water or ion-exchange water, and then wipe remaining water drops off before use.

  

WARNING: Wear safety goggles and protective gloves during work.
  Exposing your eye to solvent may result in loss of eyesight.

  If solvent gets into your eyes, rinse your eyes with running water at once and then see a doctor.

 

CAUTION: When replenishing the internal reference solution, handle the pH electrode with care.
  The stem tube and the end of the pH electrode may be damaged if exposed to a heavy load because they are made of glass. The broken glass may also result in injury.

 

1. Turn off the instrument.

 

2. Uncover the refilling port (a) of the pH electrode.
  CAUTION: With the electrode holder stored in the main unit, uncover the refilling port (a) slowly while pressing the side (b) of the pH electrode with your finger.
    The glass section of the pH electrode may be damaged. The broken glass may also result in injury.

  

  NOTE: When uncovering the refilling port, take care not to touch the glass section of the pH electrode.

 

3. Pull the knob (a) of the electrode holder to draw the slider out.

  

 

4 With a dropper, refill the pH electrode with new internal reference solution up to the position (a) through the refilling port.

  
  HINT: You can draw the slider out and then tilt the electrode holder for ease of operation. Be sure to tilt the electrode holder until it comes in contact with the slider.
  NOTE:

    • When tilting the electrode holder, take care not to touch the glass section of the pH electrode.
    • Inject internal reference solution slowly to prevent it from spilling. Wipe off spills with a piece of paper wiper.

 

5. Put the electrode holder back in a vertical position.

 

6. Push the knob of the electrode holder to set the slider back in place.

 

7. If you continue using the instrument, keep the refilling port open.
  If not, close the refilling port.