The reservoir is one liter. The airated sample is between 10 and 20 ml I think. The water reservoir is keptair tight so chances of evaporation is minimal.A few additional questions:
1. How large is the seawater reservoir? How large is the aerated sample? The question arises as to how much evaporation will result in a dry climate from aerating some portion of it over and over for weeks without checking changes due to concentrating effects and salinity.
I checked with them on the boron and they said its addressed in the product.2. Borate typically accounts for a few percent of alk, and the amount depends on pH. Have you evaluated the potential error caused by variable boron levels in typical tanks? It’s not a big deal, generally, but if one is claiming accuracy levels to within 0.1 dKH or better, it likely is important.
As long as the water in the reservoir is stable at the beginning, it will remain stable over time. Even an unstable water source from a newly set-up tank will stabilize after a certain period. Therefore, regular monthly calibration is done after it stabilizes to thoroughly define its value. We will be more than happy to send you over a unit to you so that you can see and experience it first hand.3. You write:
“Stability in reference seawater quality is crucial for accurate KH measurements.”
How will users know the alk stability in the reservoir for days or weeks?
I checked with them on this and looks like the scale of the PH graph is not defined and they just have it there for reference. The PH data is not available for customers and I have asked them to make it available.4. Can you clarify what the scales are on this graph you posted. It looks like the pH scale is missing.