refractometer calibration

[sphelps]

Originally Posted by Nano

really?
but water quality varies where ever you go, so personally wouldn't use tap water for my refractometer
especially considering the poor water quality we have in Wetaskiwin

Yes really, my tap water isn't great here either, sitting at around 300ppm. However the point wasn't to tell you to use tap water but rather your RO water is perfectly fine for calibrating. At the end of the day do you feel best with but you are wasting your time bringing your refractometer to a LFS for calibrating. They will either use RO water or a calibration fluid, however unless the calibration fluid is new (more likely been sitting around for long time) you probably run more risk with that being contaminated.

As for temperature ideally what you use to calibrate should be close to your tank temp as far I as know, however IME this makes little difference as well as long as it's pretty close, ie room temp is fine.

I encourage anyone to try calibrating their refractometer with proper solution and comparing the results for themselves. I only only posted this to prevent the need for others to try such an experiment and put to rest the myth of inaccurate refractometers. Now I'm not saying there ins't error involved however the errors we are talking about are in the ppm range while our equipment measures in the ppt range with is 1000 times greater. You simply can't measure that kind of error with our refractometers nor can you even calibrate the device that accurately anyway.