HydroFlex® as RHE (Reversible Hydrogen Electrode)
The most common use of HydroFlex in the daily lab
routine certainly is the application as RHE. You simply dip HydroFlex
into your solution, directly. The advantages are obvious. You don't
need a liquid junction, you don't have diffusion potentials and you
don't contaminate your solution by ions flowing out of your reference
As HydroFlex needs no maintanance except the regular exchange of the H2-Cartridge every 6 months, it is very well applicable for long-term tests.
HydroFlex® as NHE (Normal Hydrogen Electrode)
HydroFlex works as a NHE, if you put it into hydrochloric acid at a concentration of 1 mol/l and ambient pressure. The potential differences between a NHE and a standard hydrogen electrode are small while the experimental complexity is easily manageable.
HydroFlex® as SHE (Standard Hydrogen Electrode)
The experimental complexity of using HydroFlex as SHE is comparably high. In this case HydroFlex has to be dipped into a solution with hydrogen ion activity of 1 mol/l. The temperature has to be 298,15 K (77 °F) and the pressure has to be 1013,3 hPa (14,697 psi). As the verification of these standard conditions is challenging, the use of HydroFlex as SHE usually is irrelevant in the daily routine.
|NaOH||sodium hydroxide (caustic soda)|
|KOH||potassium hydroxide (caustic potash)|
|NaCl||sodium chloride (common salt solution)|
|H2SO4 < 50 %||sulphurir acid|
|HNO3 / HCl||nitrohydrochloric acid (aqua regia)|
If you are looking for a solution not mentioned in
the table above, it does not necessarily mean that HydroFlex®
can't be used in your application. It only means that we did not yet
Please do not hesitate to contact us in this case!