Refractometer & Hanna Calibration

[RoachF4]

Hello all,

I was hoping someone could help clear up a few things as I've searched the forums for awhile now and keep coming up with mixed results.
I have a 6 year old Marine Depot Refractometer that says to calibrate with distilled water, but I've read that this can be unreliable.
I also have a Hanna Seawater Refractometer (digital meter) that is also calibrated with distilled water. I bought some Pinpoint Salinity Calibration fluid (53.0 mS) in an attempt to calibrate both instruments, but the results were way out of bounds with the Marine Depot one and the Hanna wouldn't register the calibration fluid (error message).
So, is there another method for calibrating these two instruments or is there a different type of fluid that I should be using? I'm having some issues with my tank right now and I'm trying to rule out all possibilities. Thanks for your time.

Matt

 

[Percula9]

What issues are you having with the tank? I would calibrate the Marine depot refractometer with the calibration fluid and go with that. The fact that the digital meter gives an error message could be an indication of a malfunction. If the depot refractometer is also a problem,take a sample of water into your fish store and have then check your salinity against your meter.

 

[dan-in-gr]

Hi, I have a D-D refractometer and it is calibrated by RODI water as recommended, later I purchased the 35 calibration solution for that and another cheaper reflectometer. My D-D was spot on, the cheaper one requires the solution only, I would go with the person above recommendation and calibrate the Marine Depot one and set other to it. See if someone nearby can verify results with there refractometer.

 

[bertoni]

This article discusses a fairly simple way to make a check solution:

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

I'd probably start there.

 

[Dr. Reef]

i have wilwakee digital refrectometer and it also states to use distiled water for recal. i have done so with rodi water and is dead on compared to any refractometer. i also have a BRS refractometer and they both are on spot when it comes to salinity.

 

[xray]

I have a cheaper refractometer and have always used distilled water till last week when I purchased some pin point solution. My meter was off by 5 points. I also made up randys test solution and got the same results. If you read randy's article on salinity test meters it gives a great explanation of how meters can be off as the salinity climbs so when you use distilled water it is correct at 0 but as it goes up the scale it has an increase in error so it is better to calibrate for the end result.