Calibrating Refractometer

TexanTrail · 09/30/2009, 06:40 PM

I just bought a C-scope refractometer. It says to use distilled water to calibrate it. Can I use the RO/DI water that I'm filling my tank with? Yes, I have a RO/DI machine.

Thanks,
David

Duff Man · 09/30/2009, 06:47 PM

You will get the best results if you use calibration fluid. It's pretty cheap. I used to calibrate mine with ro/di. When I used the fluid, I saw I was off by 0.002 or so.

steelersfan · 09/30/2009, 06:58 PM

Quote:

Originally Posted by Duff Man

You will get the best results if you use calibration fluid. It's pretty cheap. I used to calibrate mine with ro/di. When I used the fluid, I saw I was off by 0.002 or so.

+1 I would recommend using the following caliberation fluid.

http://www.thefilterguys.biz/refractometers.htm

Mike31154 · 09/30/2009, 10:32 PM

Checked my water today in preparation for a water change and salinity appeared to be a tad high. Used some RO water to check 0 level on the refracto and it read .001 high. Adjusted zero with RO water and that brought the salinity reading down by exactly .001 at the saltwater range. So in my case, there appears to be no loss of linearity on the scale between 1.000 and 1.025 and apparently no need for calibration fluid.

TexanTrail · 10/17/2009, 05:54 AM

I order some calibrating solution and it came in yesterday. WOW, there was 5 ppt difference. Salinity went from 1.026 to 1.023 after calibrating. Thanks for the heads up guys!!

09/30/2009, 06:40 PM	#1
TexanTrail Registered Member Join Date: Aug 2009 Location: Kaufman, TX Posts: 56	Calibrating Refractometer I just bought a C-scope refractometer. It says to use distilled water to calibrate it. Can I use the RO/DI water that I'm filling my tank with? Yes, I have a RO/DI machine. Thanks, David

09/30/2009, 10:32 PM	#4
Mike31154 Registered Member Join Date: Apr 2008 Location: B.C. Canada Posts: 1,555	Checked my water today in preparation for a water change and salinity appeared to be a tad high. Used some RO water to check 0 level on the refracto and it read .001 high. Adjusted zero with RO water and that brought the salinity reading down by exactly .001 at the saltwater range. So in my case, there appears to be no loss of linearity on the scale between 1.000 and 1.025 and apparently no need for calibration fluid. __________________ Mike Current Tank Info: 77g sumpless sw with rock, sand, a few critters, fishes & polyps. Lights, pumps.....

09/30/2009, 06:47 PM	#2
Duff Man Registered Member Join Date: Feb 2007 Location: Chicago's far NW burbs Posts: 629	You will get the best results if you use calibration fluid. It's pretty cheap. I used to calibrate mine with ro/di. When I used the fluid, I saw I was off by 0.002 or so.

10/17/2009, 05:54 AM	#5
TexanTrail Registered Member Join Date: Aug 2009 Location: Kaufman, TX Posts: 56	I order some calibrating solution and it came in yesterday. WOW, there was 5 ppt difference. Salinity went from 1.026 to 1.023 after calibrating. Thanks for the heads up guys!!