How To Calibrate Red Sea Seawater Refractometer?

[spongetone]

So-simply put-I have the Refractometer and the calibration fluid labeled "SG 1.026. 35 ppt. What next? I know there is a cap covering a tiny screw. I just don't know the process and the directions aren't clear. Also, how often to calibrate?

Thanks!

 

[MondoBongo]

here are some isntructions:

http://www.redseafish.com/red-sea-salts/seawater-refractometer-salinity-test/

 

[Clownfish Chris]

First, Put some celebration fluid on the lens. Check the reading. Then, take the cap off and turn the screw a little. Check the reading again. You should see that it moved. Set the reading to match the calibration fluid.

 

[Wolfex]

How To Calibrate Red Sea Seawater Refractometer?

I should do this as I have been calibrating at 1.000 with RO/DI water.

 

[hkgar]

Calibrating with RO/DI water does not gurantee it will be accurate at 35 ppt or 1.026 SG. You need to use 35ppt calibration fluid.

By the way make sure the calibration fluid is tightly capped as any evaporation will mess it up.

I calibrated mine to 35 ppt many months ago and check periodically and it hasn't changed. If it ever does i would be inclined to blame the calibration fluid now.

 

[spongetone]

Thanks so much everyone for the posts! You folks are great!!

 

[Caurimare]

correct me if I am wrong but I am pretty sure Red Sea recommends calibrating their refractometer with RODI water and it has to be calibrated before every single use!!! and use the 0 PPT scale to calibrate.

 

[hkgar]

Calibrating with 0 tds ro/di water does not provide for accurate measurement of saltwater at 35 ppt. There is a curve adjustment so it doesn't work. Everyone who calibrated wit ro/di water, myself included, and then calibrated with 35 ppt calibration fluid found the readings had bee significantly off.

 

[Caurimare]

Well both Red Sea instructions and their customer service departments not only recommends but they tell you RODI water is the correct way to calibrate their refractometer, I will give them a call so I can find out the reason.
Hopefully they are right because that is how I have being doing it.

 

[Grkgod36]

I used both and there was no real difference

 

[johnzimm]

Calibrating with 0 tds ro/di water does not provide for accurate measurement of saltwater at 35 ppt.

According to their video, the new seawater refractometer should be calibrated with RODI. See link to video. But the same temperature of the test water and refractomiter is vary important.
https://youtu.be/fXY6IycuTdE