Refractometer / Hydrometer Test

[phb63]

A few friends put them to the test today. With the Deep Six water tested at 1.023 With the Instant Ocean 1.028 and with my new Refractometer from Saltwaterfish.com 1.030. Now which one do you trust to be most accurate? I know some say the number is not as important as keeping it constant. I understand that to a point but I would like to keep it constant at an accurate 1.023 not 1.030. I just received the refractometer today it was already perfectly calibrated and very simple to use. Not as quick as just dipping the hydrometer but I hope more accurate. Great price also. Any Thoughts?

 

[gwh57]

Originally Posted by phb63
A few friends put them to the test today. With the Deep Six water tested at 1.023 With the Instant Ocean 1.028 and with my new Refractometer from Saltwaterfish.com 1.030. Now which one do you trust to be most accurate? I know some say the number is not as important as keeping it constant. I understand that to a point but I would like to keep it constant at an accurate 1.023 not 1.030. I just received the refractometer today it was already perfectly calibrated and very simple to use. Not as quick as just dipping the hydrometer but I hope more accurate. Great price also. Any Thoughts?
A refractometer needs to be calibrated with calibration fluid. A hydrometer is a close guess as to what the SG reading is. IMO

 

[schadiest1]

After a refractometer is calibrated, I believe that will be your most accurate reading. Hydrometers don't seem to be very accurate at all.

 

[phb63]

Yes it was calibrated using distilled water. It was set perfect I hade to make no adjustments!

 

[mpls man]

Originally Posted by gwh57
A refractometer needs to be calibrated with calibration fluid. A hydrometer is a close guess as to what the SG reading is. IMO

i don't think you need to use a calibration fluid for a refractometer, i have 1 and just use r/o water...never had a problem.
salinity should be around 1.025

 

[gwh57]

Originally Posted by MPLS MAN
i don't think you need to use a calibration fluid for a refractometer, i have 1 and just use r/o water...never had a problem.
salinity should be around 1.025
No, it is not nessessary, but why spend good money for a piece of equipment because you want to get a more accurate measurement for SG and then not spend a few more dollars to make sure it is accurate.
If you do some research on refractometers you will find that not all of them are accurate when calibrated with RO and set to zero. When you do that you only know that it is accurate at a SG of zero. It could be off when reading highter values like we use. It is always best to calibrate at or near the point where you plan to measure. How do you know that yours is accurate @ 1.025?

 

[phb63]

Nothing said in the directions about using a calibration fluid but did say to use r/o or distilled water.
:thinking:

 

[gwh57]

Originally Posted by phb63
Nothing said in the directions about using a calibration fluid but did say to use r/o or distilled water.
:thinking:
That is the cheapest, fastest way not the most accurate way.