I have a question about vst refractometers.
I own a VST II and yesterday I was explaining a friend who got a VST III how to use it. We tested different samples and there was a big difference between the tds readings, the VST III was 0.7% higher than the VST II. Both were calibrated the same say with the same distiled water and the sample came from the same pipete. Is there something wrong with the II or is the III more accurate?
Have you contacted VST support? They might have a clue. If I recall correctly they use to answer somehow quickly. Would you mind to share their answer?
Are you measuring filter or espresso? It looks like there were multiple versions of the VST II according to the brochure, with different accuracy depending on what is being measured.
