Randy's DIY Refractometer Calibration Fluid - Kosher Salt OK?

DeathWish302 · 04/14/2008, 08:19 AM

I have seen Randy's recipe for calibration fluid for a refractometer in I believe Reefkeeping Mag. In this article he stated he used 6.2g of Morton salt. I have Kosher salt already (not iodized) and would prefer to use this instead of buying more. Any problems with this substitution? Due to crystal size/shape differences, I will measure this in the Materials Lab at work so that the correct weight is used.

Thanks,
DW302

Boomer · 04/14/2008, 10:18 AM

That will be fine DW, as long as you are going to measure it out as you stated

Kosher not only does not contain any Iodine but also none of the Sodium ferrocyanide, which is a free-flow agent. STD lab grade cal solutions use Kosher more or less, pure NaCl.

DeathWish302 · 04/14/2008, 01:23 PM

Thanks Boomer!

I thought the lack of anti-caking agents and iodine would be better, but was uncertain if Randy accounted for these in his calculations for the proper proportions.

DW302

Randy Holmes-Farley · 04/14/2008, 02:11 PM

No, I did not specifically take them into account.

DeathWish302 · 04/16/2008, 09:56 PM

Randy - The DIY solution worked out fine and it appears is as good as the high dollar stuff we have at work. I cannot mention the company due to internal issues at the moment, but we are a tier 2 automotive company that uses salt spray testing. The guys in the test lab were surprised their "ASTM-certified" calibration fluid read very similiar results as your recipe for the DIY fluid. Cost me $1.69 for the 1L of Diet Dew, purified water = free from the lab, and the kosher salt I had. Not bad for less than $2 and 25 minutes out of my cube dungeon.

Thanks for the article.

Frank

reef_doug · 04/16/2008, 10:55 PM

Quote:

Originally posted by Boomer
That will be fine DW, as long as you are going to measure it out as you stated Kosher not only does not contain any Iodine but also none of the Sodium ferrocyanide, which is a free-flow agent. STD lab grade cal solutions use Kosher more or less, pure NaCl.

FWIW... I remember Morton Kosher having more sodium per measuring cup than Diamond Crystal Kosher. Would this impact the volumes in the DIY recipie?

Boomer · 04/16/2008, 11:32 PM

Volume yes Doug but not weight

Justy take some to the drug store and have them make-up a 3.65 % solution.

963.5 mL RO/DI and 36.5 grams of Kosher

Then cal the refract to read 35 ppt or 1.0264 with this solution.

Or just go buy some Pinpiont 53 mS and the same, cal to read 1.0264 or 35 ppt

04/14/2008, 08:19 AM	#1
DeathWish302 Clown Hoarder Join Date: Apr 2001 Location: Wixom, MI Posts: 1,614	Randy's DIY Refractometer Calibration Fluid - Kosher Salt OK? I have seen Randy's recipe for calibration fluid for a refractometer in I believe Reefkeeping Mag. In this article he stated he used 6.2g of Morton salt. I have Kosher salt already (not iodized) and would prefer to use this instead of buying more. Any problems with this substitution? Due to crystal size/shape differences, I will measure this in the Materials Lab at work so that the correct weight is used. Thanks, DW302

04/14/2008, 10:18 AM	#2
Boomer Bomb Technician (EOD) Join Date: Aug 2002 Location: Duluth, Minnesota Posts: 11,883	That will be fine DW, as long as you are going to measure it out as you stated Kosher not only does not contain any Iodine but also none of the Sodium ferrocyanide, which is a free-flow agent. STD lab grade cal solutions use Kosher more or less, pure NaCl. __________________ If you See Me Running You Better Catch-Up Seawater Chemistry, Geology, ID Marine Life, Collecting Science Books, Explosives Technology, Audiophile An explosion can be defined as a loud noise, accompanied by the sudden going away of things, from a place where they use to be.

04/14/2008, 02:11 PM	#4
Randy Holmes-Farley Reef Chemist Join Date: Apr 2001 Location: Arlington, Massachusetts Posts: 81,937	No, I did not specifically take them into account. __________________ Randy Holmes-Farley Club 65535 Current Tank Info: 120 mixed reef

04/16/2008, 11:32 PM	#7
Boomer Bomb Technician (EOD) Join Date: Aug 2002 Location: Duluth, Minnesota Posts: 11,883	Volume yes Doug but not weight Justy take some to the drug store and have them make-up a 3.65 % solution. 963.5 mL RO/DI and 36.5 grams of Kosher Then cal the refract to read 35 ppt or 1.0264 with this solution. Or just go buy some Pinpiont 53 mS and the same, cal to read 1.0264 or 35 ppt __________________ If you See Me Running You Better Catch-Up Seawater Chemistry, Geology, ID Marine Life, Collecting Science Books, Explosives Technology, Audiophile An explosion can be defined as a loud noise, accompanied by the sudden going away of things, from a place where they use to be.

04/14/2008, 01:23 PM	#3
DeathWish302 Clown Hoarder Join Date: Apr 2001 Location: Wixom, MI Posts: 1,614	Thanks Boomer! I thought the lack of anti-caking agents and iodine would be better, but was uncertain if Randy accounted for these in his calculations for the proper proportions. DW302

04/16/2008, 09:56 PM	#5
DeathWish302 Clown Hoarder Join Date: Apr 2001 Location: Wixom, MI Posts: 1,614	Randy - The DIY solution worked out fine and it appears is as good as the high dollar stuff we have at work. I cannot mention the company due to internal issues at the moment, but we are a tier 2 automotive company that uses salt spray testing. The guys in the test lab were surprised their "ASTM-certified" calibration fluid read very similiar results as your recipe for the DIY fluid. Cost me $1.69 for the 1L of Diet Dew, purified water = free from the lab, and the kosher salt I had. Not bad for less than $2 and 25 minutes out of my cube dungeon. Thanks for the article. Frank