Refractometer Calibration??

AngeloM3

New member
How about the ones that state "No calibration needed"? I was told for those to use distilled or RO water.
 

jdieck

New member
<a href=showthread.php?s=&postid=9857834#post9857834 target=_blank>Originally posted</a> by AngeloM3
How about the ones that state "No calibration needed"? I was told for those to use distilled or RO water.
Most salinity refractometers in the hobby are designed and manufactured to measure salt water and not sea water, seawater has a different refraction index than salt water. If you use distilled or RO/DI water to calibrate the zero then when you read the salinity at natural sea water level (1.0264) you will not be actually reading salinity of seawater but that of salt water which will read a salinity lower than what is needed.
To compensate for this you need a salinity reference solution like the one mentioned above and calibrate the refractometer at the 1.0264 using the solution.
 

AngeloM3

New member
I'm a little confused by the directions how to make the correct sollution....

It says to add 1/4 cup Mortons Salt and 1 tsp of salt etc....

The 1 tsp of salt... is that table salt or reef salt?
 

jdieck

New member
<a href=showthread.php?s=&postid=9870670#post9870670 target=_blank>Originally posted</a> by AngeloM3
I'm a little confused by the directions how to make the correct sollution....

It says to add 1/4 cup Mortons Salt and 1 tsp of salt etc....

The 1 tsp of salt... is that table salt or reef salt?
One cup+1 Teaspoon of Morton salt. In other words a bit more than one cup.
 

blkdrgn

Premium Member
The directions for my Captive Purity Refractometer with Calibration Dial that I got yesterday says to use distilled water. I guess I have to read the whole thing.
 

AngeloM3

New member
<a href=showthread.php?s=&postid=9870709#post9870709 target=_blank>Originally posted</a> by jdieck
One cup+1 Teaspoon of Morton salt. In other words a bit more than one cup.

Ahhhhhh thanks for the clarification.
 

Sparty00

New member
I just got mine today, and it says to use distilled water as well.....

What is the right way to calibrate these things?
 

AngeloM3

New member
From my understanding.......... using distilled or RO water to calibrate is OK... but that is assuming it left the manufacture or LFS calibrated correctly.


To be %100 positive its calibrated correctly is to use the method on the links provided above.
 
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