・Product name (model name)
・Amount of component included in test sample
・Details on measurement results and conditions
Also, if possible please send the measurement conditions, measurement data, graphs and other printed results in the form of PDF attachment, etc. to .
We think we would be able to provide more suitable advices.
A3. The tube attached to the pump gradually degrades as it is used.
As the tube degrades, this results in weakened pump capabilities.
Although it depends of the frequency of use and the test reagents, assuming about 4 hours of use per day it must be replaced approximately once every 6 months.
Please see the instruction manual for information on how to replace it.
One thing to note is that the tubes for the pure water emission pump and the solvent emission pump are made of different material.
Please see the instruction manual to confirm the type of material for the tube of the pump you are using and attach the proper material.
A4. It should not have an impact on inflection point detection but it does have an impact on set point detection.
Depending on differences in dilution levels, the starting pH will be different. With a standard of 50mL pure water, a 5mL variation will be a 10% difference, which can result in an approximately 0.1pH difference.
We also recommend being accurate to ensure that the amount of dilution is uniform.
・What are indicator electrodes?
When attempting to measure a solvent’s pH or oxidation-reduction potential, glass electrodes and metal electrodes change their electrode potential in a fixed relation to the concentration of the solvent.
・What are reference electrodes?
These are standard electrodes used to measure the electromotive force of indicator electrodes, and they maintain a fixed electrical potential unrelated to the solvent’s pH and the concentration of the oxidant and reducing agent.
They are also called comparison electrodes or collated electrodes.
A feature of reference electrodes is their liquid junction, and when the internal liquid and test solution come into contact in this liquid junction the internal pole of the reference electrode and the test solution become electrically connected.
A representative structure of the liquid junction is shown in the figure below.
In the potentiometric titration apparatus, each of the above electrodes is immersed in a solution, and the potential difference indicated by the electrode is measured to find the end point.
A6. Structurally, the RE-201 type reference electrode’s internal liquid may decrease due to the effects of temperature and air pressure, and some crystalized internal liquid may be stuck onto the protective cap.
After purchasing, first wash these attached crystals with pure water and remove the protective cap.
We recommend confirming and adjusting the degree of attachment of the sleeve and storing it soaked in pure water.
Put 60-70mL of pure water into a 100mL beaker and submerge the internal liquid below the liquid surface.
(Please maintain this state avoiding any of the pure water or internal liquid running out.)
As a general rule, replenish the internal liquid when its level becomes about 2cm away from the replenishment port of electrode,(The structure differs depending on the electrode, so please judge the estimated replenishment timing depending on the location of the internal electrode element, etc.)
If the electrodes are connected to the device, please be sure to turn the device’s power off and disconnect the electrodes.
Next, please take off the cap from the replenishment port and replenish the internal liquid, filling it to about 5mm below the replenishment port of electrode in a perpendicular state (to the extent that it will not overflow from the replenishment port if the electrode is slightly shaken).
If you let the internal liquid of the electrode run out it will not only be impossible to conduct proper detection but also may damage the electrode, so please check the amount of internal liquid regularly.
A8. Indicator electrodes and reference electrodes combined into 1 are referred to as composite electrodes.
At our company we have glass-reference composite electrodes, silver reference composite electrodes, and platinum reference composite electrodes.
They are all functionally similar, but they should have the following features and points of caution.
Because a maximum of 3 electrodes will fit into the electrode holders, when conducting various titrations on the same sample the electrodes may not fit in place.
In such cases it is convenient to use composite electrodes.
・When an electrode is damaged it is replaced 1 individual electrode at a time, but composite electrodes are replaced 2 at a time. ・In measurement of non-aqueous neutralization values, etc. the liquid may enter into a composite electrode so please avoid using composite electrodes. ・The sleeve of composite electrodes cannot be washed (excluding GR-511B).
“There is an outflow of internal liquid, within 12 mm within 24 hours” (Confirm with the inner liquid near the replenishment port, remove the cap of the internal solution replenishing port, and keep the tip of the electrode in the atmosphere).
The movable sleeve type electrode changes its outflow amount depending on how the sleeve is lowered. If it is loose it may be exhausted.
If your electrode does not fall into the above standards, please loosen the sleeve once and check it again properly.
A11. Although it depends on the nature of the sample (principle differences, reaction with measurement reagents), firstly the measurement range of the respective titration methods is the selection standard.
Please see the following chart as a reference.
Coulometric titration method
Volumetric titration method
Iodine which is generated through electrolysis reacts with moisture and the amount of moisture is calculated from the volume of electricity that circulates the consumed iodine.
The amount of moisture is calculated from the volume of Karl Fischer reagent dropped in.
①You must either remove the crystals that have formed and clogged up the end of the burette tip or replace the burette tip.
【Please be careful】
When cleaning, if you change the shape of the tip, the liquid may stop dripping out normally.
Furthermore, a tube is press-fitted to the end of the burette tip and it may come out of place, so please take caution.
②Fixing the burette syringe in place.
Please remove the syringe from the burette head and confirm the vertical motion with a push rod.
If it is not working normally it will be necessary to replace the syringe.
A15. You can replace the burette you are currently using with a burette of a different capacity.
You can use 5 types of cylinders: 1, 5, 10, 20 (standard) and 50mL.
When changing them, you can do so by setting the capacity setting fixture on the underside of the burette head to match the capacity you are using.