Refractometer calibration solution?

[fishresponse]

What does everyone use to calibrate their refractometer?

 

[Boboli]

My refractometers instructions calls for RO water.

 

[OregonReefer2]

http://www.bulkreefsupply.com/catalog/product/view/id/708/

 

[BlakDuc]

RODI water and set the line to 0.0

 

[benzrider85]

http://www.bulkreefsupply.com/catalog/product/view/id/708/

This is what I use. I have read that your average hobbyist refractometer isn't that accurate at scale, so it's best to calibrate it on a solution that is closest to what you will be testing.

 

[Dapg8gt]

DIY from here.. Table salt and RODI.. Pretty much free 35% solution.. Also states why you should not use 0TDS with some refractometers.

http://reefkeeping.com/issues/2004-06/rhf/index.php

 

[whitesquall]

This is what I have been using:
http://premiumaquatics.com/store/me...ode=PA&Product_Code=REFRACT-SF&Category_Code=
I check calibration before every use, piece of mind that i'm getting an accurate reading.

Hth's
-Alex.

 

[downbeach]

Your refractometer should be calibrated using a solution known to have a refractive index close to that of the samples to be tested. So, it would be prudent to use this, or similar solution.

http://reefkeeping.com/issues/2006-12/rhf/index.php#11

 

[hoaglanddiver]

+1 on Dapg8gt's post. However, I found it hard to measure the salt w/ my standard scale and had to purch a much more "sensitive" scale... cost me about same as ordering calib solution on line + shipping... figure I can use scale many times to make own for cost of one solution+shipping

 

[popebosephus]

I use the BRS calibration solution. I agree that calibrating against known solution at your desired levels is more effective than testing against RO.

 

[aandfsoccr04]

http://www.bulkreefsupply.com/catalog/product/view/id/708/

This is what I also use.

 

[zab34]

BRS solution, Dont calibrate to 0 I hear that isn't accurate around that scale.

 

[fishresponse]

http://www.bulkreefsupply.com/catalog/product/view/id/708/

So is there any difference to using this calibration fluid when it's specifically designed for a digital probe rather than a hand held refractometer?

 

[fishresponse]

Your refractometer should be calibrated using a solution known to have a refractive index close to that of the samples to be tested. So, it would be prudent to use this, or similar solution.

http://reefkeeping.com/issues/2006-12/rhf/index.php#11

Good article. I now see why sea water is better to use for calibration.

 

[jeremy K]

Just to add, using a calibration solution is more accurate, but only if the calibration solution is new. Usually the calibration solutions come in very small bottles, and if you leave them uncapped for even a short time, a tiny bit of evaporation will make a difference in the concentration.

 

[fishresponse]

Thanks Jeremy

 

[OregonReefer2]

So is there any difference to using this calibration fluid when it's specifically designed for a digital probe rather than a hand held refractometer?

Taken straight from the link:
standardized fluid for calibrating PINPOINT Salinity Monitors as well as refractometers. PINPOINT Salinity Calibration Fluid calibrates to sg 1.026 or 35ppt

The problem with using RO/DI water is the further you get away from your calibration point the wider the error margin

 

[fishresponse]

The instructions say to calibrate at 77 degrees. My question now is do you allow your refractometer to get up to 77 degrees before starting the calibration process? Or do you simply just calibrate with no temp compensation time? I've noticed the salinity varies if let the unit sit at room temp vs sitting in your hand... Just as an example. Thoughts?

 

[OregonReefer2]

Don't worry about. Just calibrate it with your refractometer at room temp. The solution (or SW) will very quickly adjust to the temp of the meter. The difference is pretty minor. I wouldn't worry about it unless you run a coldwater tank

 

[SeedlessOne]

RODI water and set the line to 0.0

This in incorrect.



You need calibratin solution.