Refractometer calibration solution

[tfp]

anyone with a refractometer might want to check out this thread:

Refract Thread

i purchased a couple bottles of the pinpoint calibration solution and will donate a bottle to our club at the next mars meeting so people can calibrate their refractometers as needed.

i'm glad to report that my meter that was bought in our group buy a couple years ago measured spot on at 35ppt with the solution

tim

 

[dots]

RO/DI water doesn't work.....oopps read the link.......first my swingarm wasn't good enough.....now my Marine Depot special isn't.......man....you buy and buy and where does it get you?

 

[Brian Prestwood]

Doug/Tim

I scanned the thread. It looks like calibrating to 0 with RO/DI should work if you have a good refractometer.

If you have a poor quality refractometer calibrating in the range (1.026) you expect your sample to be in is better but not always accurate.

Is that what you came away with?

 

[tfp]

brian, my interpretetation was pretty much the same. but as reference, the solution should be used.

some of the refracts that were out of rodi calibration were the same models as mine so i wanted to be sure.

 

[duec22]

Well I just made the DIY std that Dr. Ron posted in there...I'll take it home and test it out tonight. I've got one of the Dr. Foster and Smith refractometers....probably not the highest quality, and I've been thinking it might be off....I'm seeing some of the same stresses on my SPS when I had high salinity before....but the refractometer says its fine....

 

[Brian Prestwood]

I'm going to calibrate mine with RODI and then test the reference to see if the RODI calibration works.

 

[duec22]

<a href=showthread.php?s=&postid=8659067#post8659067 target=_blank>Originally posted</a> by Brian Prestwood
I'm going to calibrate mine with RODI and then test the reference to see if the RODI calibration works.

ditto..I know there are a couple people using the same refractometer as me (dr. F&S)...so if you run checks be sure to state what brand you are using...

 

[dots]

I noticed that most refractometers, or measuring devices for machine shops measuring oil sg....seem to be the same blue one that you see all the time......so is that the bad or good one?......but yeah, thats what I got when I scanned the article Brian,........pretty much you ain't cool unless you got a pinpoint now it seems.

But I am little perplexed why a liquid that is supposed to not have any dissolved minerals in it and pure, why the RO/DI can't be used as a standard......I remember it was good enough in my chem class.

Maybe I should read it again......probably a design flaw, rather than a liquid flaw.

 

[duec22]

Ok just did the tests...RO/DI set at zero...1.0264 std. tested between 1.026 and 1.027. So looke like the the DR. Foster and Smith refractometer, or at leat mine, works fine when calibrated at zero with RO/DI.

 

[Brian Prestwood]

I got my istructions out. They say to calibrate with distilled water. My refractometer is a Hauke Instrument Company RHS-10ATC. In other words, automatic temp compensation made it china.