How often do you calibrate your refractormeter??

[kamloops_reefer]

you wouldn't think that a name like 'vertex' would offer a product which sounds more touchy than others?

Perhaps I'm just too rough on precision tools - but if I calibrate mine (I use the solution as well) and then set it down on the table a couple times (about as diligent if it was a glass of water, so not too gentle, not too rough) you might be surprised to find that it will change on you.

I usually have to calibrate the unit twice, first time could have left over residue from previous testing on the glass. Second is a for sure check - and as well as the tank water, check twice or even three times, trying not to set it down or bump it into anything (I usually just dip the entire end of the Ref. into the tank)