Refractometers

[BigC]

Hi,
I am about to purchase a refractometer (again please excuse my ignorance) I have got the gist of how one works but I'm a little clueless when it comes to the calibration of the instrument. Someone told me to calibrate it to zero with pure Reverse Osmosis water.!!! Is this is correct and if so does the RO water need to be a required temp, the same as the aquarium. Please enlighten me as to the testing and calibration process involved in setting up a refractometer, also does it need to be calibrated before every use.
Lengthy answers appreciated so as I can get my dumb freshwater head around this new piece of kit.
Regards
BigC

 

[@ombomb]

I think the right temp is about 20C so room temp which is the same temp the tank water will be when you test it.

Use pure RO water.

I check mine every few weeks to make sure it's correct.

Simple!

 

[Ricey]

better still, get a temp. compensated one!

http/www.osmotics.co.uk/temperature-comp...6.html?cPath=39

 

[BigC]

better still, get a temp. compensated one!

I like the look of that one Ricey and a great price too.
Regards
BigC

 

[andywg]

Though from reading on RC it appears many refractomeeters for the hobby do not calibrate well when using RO to hit 0. That is, they tend to read SW inaccurately when calibrated in such a manner.

It appears you are better off making a known salinity solution (one very close to sea water) and calibrating to that level. There are recipes on RC for this.

 

[SkiFletch]

Here's the article Andy was referring to: Refractometers and Salinity Measurement

 

[BigC]

Some good articles on that site.

 

[SkiFletch]

Yes very. Randy Holmes-Farley is like the mecca of reef chemistry knowledge

 

[N1z]

I was thinking for my bday getting this bad boy instead as the idea of looking through a small scope seemd silly to me.
link