Refractometer Opinions

[cyeater]

I plan on purchasing this refractometer from premiumaquatics.com:

http://www.premiumaquatics.com/Merc...duct_Code=REFRACT-PA&Category_Code=Hydrometer

and is this the right solution for calibration?

http://www.premiumaquatics.com/Merc...t_Code=PIN-SAL-FLUID&Category_Code=Hydrometer


Let me know you opinions on this item

 

[drummereef]

Those are fine refractometers. The preferred method for calibration is below.


Reef Aquarium Salinity: Homemade Calibration Standards
http://reefkeeping.com/issues/2004-06/rhf/index.htm

 

[cyeater]

Where exactly does it say how to calibrate in that article?

 

[drummereef]

About 1/3 the way down under "Refractometer Standard"


This 3.65 weight percent sodium chloride solution can be made by dissolving 3.65 grams of sodium chloride in 96.35 grams (mL) of purified fresh water. That amount roughly corresponds to ¼ cup (73.1 g) of Morton's Iodized Salt dissolved into 2 liters (2000 g) of water (giving very slightly more than 2 L of total volume).

For a rougher measurement in the absence of an accurate water volume or weight measurement:

1. Measure ¼ cup of Morton's Iodized Salt (about 73.1 g)
2. Add 1 teaspoon of salt (making about 79.3 g total salt)
3. Measure the full volume of a plastic 2-L Coke or Diet Coke bottle filled with purified fresh water (about 2104.4 g)
4. Dissolve the total salt (79.3 g) in the total water volume (2104 g) to make an approximately 3.65 weight percent solution of NaCl. The volume of this solution will be slightly larger than the Coke bottle, so dissolve it in another container.

 

[cyeater]

So for a dumby to understand, follow those 4 steps to calibrate that same refract that I'm looking to purchase?

 

[Runner]

Yes. I have that same refractometer.

The method above will do a good job calibrating your refractometer. I am lazy and just zeroed my out with filtered water, though.

 

[mwwhite]

PinPoint's 53 ms/cm solution works well, and is a suitable alternative to DIY.

 

[drummereef]

<a href=showthread.php?s=&postid=9738664#post9738664 target=_blank>Originally posted</a> by cyeater
So for a dumby to understand, follow those 4 steps to calibrate that same refract that I'm looking to purchase?

Yep. If you have a scale I'd measure that way but the 'rough measurement' will work just fine.