Refrac Calibration

[rsantangelo3@co]

So is D.I the prefered way to calibrate the Refrac? I mean when you set to 0 there is a marginal error on the calibration scale going all the way to 1.025. Just got mine in and was curious becasue the instructions state d.i prefered way. Also any recipes for home made cali solution? Last, I have to hold the platic/glass panel down with my hand in-order to see the blue versus clear screen. Is this common or should it appear with just shutting the viewer? All information will help.

 

[dwd5813]

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

 

[snorvich]

You need pinpoint calibration fluid (1.0264) to properly calibrate a refractometer

 

[mjk427]

I used DI water to calibrate mine and it was still off. It was reading 1.026 when It was really 1.024. I used the calibration fluid which let me know the DI methid didn't work well. I know use the DIY solution that dwd5813 posted and it works as well as the retail calibration fluid. I don't have to hold down the panel on mine to view.

 

[rsantangelo3@co]

I made it but it reads way higher than the D.I method as well as the 35ppt. Now it matches the 1.035 on the left side but I am looking for the 35ppm on the right side which is higher right? I am doing hypo so I really need help here!

 

[mjk427]

You should put the drop of the calibration solution on the refractometer then look through the eyepiece. turn the knob or screw so the line is at 35ppm on the right. It doesn't matter what it reads before you calibrate. If you made the solution correctly then it is 35ppm.

 

[rsantangelo3@co]

If I put it to 35 ppm my salinity would read 1.005. Wouldnt my fish have croaked? Also D.I cant be that far off if I get .000 for D.I calibration and then have a .010 difference from my hydormeter and the D.I calibration. In other words with the D.I calaibration there is a .003 differnece between my hydrometer and refrac. If I calibrat to solution there is over a .10 difference. My hydrometer cant be out that much and the D.I calibration

 

[rsantangelo3@co]

.010 rather

 

[mjk427]

What kind of refractometer do you have? On mine (National Industrial Supply Co) the sg 1.030 and 40 PPT are directly across from each other. So if it read 35 on the right is at 1.026 on the left.

 

[rsantangelo3@co]

who knows probebly some knock off from Dfand S it says made in China and that it. No it reads 1.035 on left which is 45 on right. Also in all articles I read to use D.I calibration for hypo

 

[mjk427]

Yours is set up correct. So 40 will be across from 1.030 and then 35 will be across from like 1.026. My point is if you calibrate to 35 on the right when you have the DIY solution on it then directly across to the left will be 1.026. I'm not sure about the DI and hypo never looked into that.

 

[dwd5813]

like they said, if you made the solution right, it will be 35ppt, or 1.0264. if you have doubts about it, pinpoint makes a solution that is around 5 bucks per bottle. i went with the pinpoint myself.

 

[luther1200]

<a href=showthread.php?s=&postid=14697210#post14697210 target=_blank>Originally posted</a> by rsantangelo3@co
If I calibrat to solution there is over a .10 difference. My hydrometer cant be out that much and the D.I calibration

I think the hydrometer could be that far off. Most hydrometers aren't very accyrate. Thats why people buy refractometers.

What kind of hydometer do yoiu have? Any one that doesn't hold at least 6" of water isn't very accurate. Unless it the glass drop in kind.

 

[mjk427]

I agree. I still use my hydrometer, but I know that it is .02 off so I shoot for 1.024 on my hydrometer knowing that it is 1.026 on my refrac. I only use the refrac once or twice a month.

 

[mg426]

Pinpoint solution here.