Refractometer calibration solution

[EvilMel]

Hey guys, I got a new refractometer and since I always a) assume they're not calibrated and b) want to calibrate with a solution near the actual salinity of what I'm measuring, I decided to make refractometer calibration solution.

I always have had a hard time thinking in terms of ppm, ppt, etc BUT once every couple of years, I trudge through relearning the chemistry and figure out the calculations. I had my calculations all worked out but I decided to check the intertubes to see what would come up if I googled "how to make refractometer calibration fluid" and I came across this cool article:

http://www.reefkeeping.com/issues/2004-06/rhf/

I just thought you guys might be interested in it. I thought it was neat and apparently it's fairly accurate!! So check it out and check your refractometers.

 

[EvilMel]

I should probably make a TDS calibration solution while I'm at it.

 

[dudemeister]

Very cool ty!

 

[Saltwaterwill]

Thank you very much Appreciated

 

[dudemeister]

Ok so who has a good scale nearby to me?

 

[ssdawood]

Ok so who has a good scale nearby to me?

If you are on good terms with your pharmacist they are very helpful.

Or street pharmacists. Lol

 

[dudemeister]

good call thx!

 

[EvilMel]

I've got some scales if need be. I can also bring my solutions to a meeting and you can bring your TDS meters and refractometers, if you want!

 

[S2minute]

Refractometer calibration solution

Hi guys, i'm not in your club but, if you would, i have a question. On the instructions for my light refractometer, it says use fresh water to calibrate. However, i also read that it should be calibrated with a stock solution made from Mortons table salt. So i read Randys page and he says mix 161 ml of water, i used ro/di, with 6.5 grams of the salt to make a 35 ppt solution, which i did. So , i then calibrated the meter with plain ro/di and found it was off by roughly 1 ppt and i adjusted. Then used the mortons salt solution and it did not read 35 ppt but, 40 ppt and i found myself 2nd guessing if i actually made to salt solution correctly. However, i calibrated that reading down to 35 ppt as a result. Then i tested my system water and it read 35ppt as well....which is what i thought it always was anyways. That sound right?

 

[thefuz]

*casts thread resurrection spell*

Anyone got a refractometer that they trust?? I bought a salinity probe and during the calibration process I dripped some calibration solution on my refractometer. While the reference solution is supposed to be 35/1.025 the refractometer reports closer to 29/1.020. This is maddening! I just want to dial this in on the new tank, dammit!!

 

[peter fumo]

I have a a bran new one you could borrow

 

[dudemeister]

Oh Mel!!!! Perhaps we will see you at the upcoming meeting and you could share some calibration fluid? That or measure out the proper amount of salt with your scales?

 

[EvilMel]

I can bring a scientific scale and/or my calibration solutions...whatever you want. The solutions are just in the freaking way at my house anyways.

Someone remind Mason to text me Saturday or Sunday and have me put it in the car. I may not check the threads in between now and then. I will try to though!

 

[thefuz]

Awesome - will do. Thanks, Mel!

 

[dudemeister]

I can bring a scientific scale and/or my calibration solutions...whatever you want. The solutions are just in the freaking way at my house anyways.

Someone remind Mason to text me Saturday or Sunday and have me put it in the car. I may not check the threads in between now and then. I will try to though!

I never thanked you for bringing this to the meeting. Works like a charm!

 

[thefuz]

I'll second that. THANKS, MEL!!!

 

[EvilMel]

Awesome. Glad I could help you guys.