2er-Set Hydrogen Cells for Mini-HydroFlex and pHydrunio

Yes, according to IUPAC convention SO5917, the hydrogen reference electrode should be used.

The Mini-HydroFlex reference electrode is designed for our test cells FlexCell and ElyFlow. However, it offers additional advantages such as adjustable length and a relatively small diameter.

The HydroFlex, on the other hand, is more robust and, with a diameter of 8 mm, follows the recommendations for the outer dimensions of  reference electrodes.

Yes, both electrodes are electrodes of the first kind. You can place these electrodes directly into any kind of electrolyte.

Yes and no.
Measuring open-circuit potentials does not require a fixed position within the cell.
However, when applying some current to the electrochemical cell and thereby creating field line curvatures, you must use a Haber-Luggin capillary to adjust the correct position. Another advantage of the Haber-Luggin capillary is that it helps to protect the hydrogen electrode from parasitic oxygen gas bubbles.

Of course that is allowed. However, you will need to perform some calculations regarding the concentration and temperature effects on the AgCl potential. Furthermore, you will get liquid junctions potentials at the ceramic frit. These liquid junction potentials can be low in diluted electrolytes. However, at concentrations above 1 mol/L, they are no longer negligible.

Yes, the replacement cells can be stored. However, please mind the best before date.

The expiration date depends on the date of manufacture.
As a general rule, you should activate the cells after about 18 months at the latest. If in doubt, just ask us.
The reference electrode itself has no expiration date. You just need to remember to use a new hydrogen cell.

There are no special storage instructions to follow.

Yes, this is very important.
The replacement cells for HydroFlex are not compatible with Mini-HydroFlex, and vice versa.
Please be sure to purchase the hydrogen cells for Mini-HydroFlex and the hydrogen cartridges for HydroFlex.

The Mini-HydroFlex reference electrode is designed for our test cells FlexCell and ElyFlow. It also offers additional advantages such as adjustable length and a relatively small diameter.
However, please keep in mind that you will need an additional test lead.

You can also use our HydroFlex when using the test cells FlexCell. You will then need an additional connector available for FlexCell-PP or FlexCell-PTFE.
Please note that our HydroFlex is not compatible with the test cell ElyFlow! You have to use the Mini-HydroFlex instead.

Yes. Because of the exact position of the reference electrode and the usage of a Haber-Luggin capillary, you always measure the correct potential. The large distance  between the working electrode and counter electrode ensures that the entire working electrode has the same potential, regardless of the position on the surface.

Usually, you should place the reference electrode in front of the working electrode. However, you can also measure the voltage drop across the membrane or measure the potential at four different positions simultaneously.