Vee gee stx-3

[Reef.]

I must have missed that part. No just room temp RODI roughly 72.

Doesn’t the instructions say to calibrate at 68f?

 

[trmiv]

Doesn’t the instructions say to calibrate at 68f?

Yes it does. Says to calibrate in a controlled environment set to 68 where both the tool and the fluid have been let to come to temperature. 72 may not be so bad, but my house runs 76-77 right now so I’d think that would make a pretty big difference.

 

[MrsBugmaster]

Great refractor meter. I use to have one and checked it several times and never had to recalibrate it in over a year. Then I dropped it on the basement cement floor. Cracked the prism.
This time around I went all out and got a Misco [HASH=65664]#PA202X[/HASH] and absolutely love this thing. But it is quite expensive.

 

[DeputyDog95]

Does everyone still like this unit? I'm looking to purchase a new refractometer. Everyone still happy?

I noticed the directions say to use distilled water, but everyone here is using RODI to calibrate? Does it matter?
I'm in FL and as the other poster said, getting my room to 68 degrees to calibrate would be near impossible. How far off would it be at 72-73?
Lastly, while I understand you're not supposed to calibrate with a calibration fluid, why wouldn't the meter read the state value of the reference fluid?

 

[trmiv]

Well I did a different thing with mine. I calibrated it to what my Tropic Marin hydrometer reads at 77 degrees. Maybe that’s not the 100% correct way to do it, but now both the hydrometer and the refractometer read the same on the same water (temperature corrected for the hydrometer) consistently which is what I was after. I really wanted the STX-3 for quick readings when I didn’t feel like dragging out a graduated cylinder.

 

[Reef.]

Does everyone still like this unit? I'm looking to purchase a new refractometer. Everyone still happy?

I noticed the directions say to use distilled water, but everyone here is using RODI to calibrate? Does it matter?
I'm in FL and as the other poster said, getting my room to 68 degrees to calibrate would be near impossible. How far off would it be at 72-73?
Lastly, while I understand you're not supposed to calibrate with a calibration fluid, why wouldn't the meter read the state value of the reference fluid?

Just got one myself, love it.

Distilled or rodi is fine, both essentially the same thing.

You are correct 35ppt can also be used, if you can’t get down to 20c just check with rodi water or 35ppt (follow randys diy method to make calibration fluid.) then see how far off the line they are, this will let you know where the correct line is for 35ppt, could just mean you are a man above or below the 35ppt but it doesn’t need calibration very often, I’m sure a couple a days a year it’s down to 20c, the rest of the time just keep a bottle of your diy solution to check it’s still reading correctly. Remember to let the refractometer stand for at least a min when testing to allow the refractometer to temp adjust.

 

[RyonFly]

"You can use the 35 ppt solution to calibrate the STX-3, no problem. That refractometer can be used in different applications so we say to zero it with distilled water. But you can calibrate it at any point on the scale as long as you have an accurate solution. I’m assuming you have a salt water aquarium and the 35 ppt is very commonly used for that application.



Ken Kreiman

Sr Category/Product Manager"

 

[DeputyDog95]

Well I did a different thing with mine. I calibrated it to what my Tropic Marin hydrometer reads at 77 degrees. Maybe that’s not the 100% correct way to do it, but now both the hydrometer and the refractometer read the same on the same water (temperature corrected for the hydrometer) consistently which is what I was after. I really wanted the STX-3 for quick readings when I didn’t feel like dragging out a graduated cylinder.

How does the hydrometer thing work? Do you have a giant graduated cylinder you fill with tank water and float the hydrometer?
If so, how do you fill it and do you pour the water back into the tank when you're done?

 

[DeputyDog95]

"You can use the 35 ppt solution to calibrate the STX-3, no problem. That refractometer can be used in different applications so we say to zero it with distilled water. But you can calibrate it at any point on the scale as long as you have an accurate solution. I’m assuming you have a salt water aquarium and the 35 ppt is very commonly used for that application.



Ken Kreiman

Sr Category/Product Manager"

The problem is finding a definitively accurate reference solution.

I didn't have much luck making Randy's. Not sure where I went wrong...

 

[trmiv]

How does the hydrometer thing work? Do you have a giant graduated cylinder you fill with tank water and float the hydrometer?
If so, how do you fill it and do you pour the water back into the tank when you're done?

Yes. I have a 500ml graduated cylinder. Only my Reefer 350 I just dunk it in the tank to fill it. On my Nuvo 20 I fill it with a measuring cup. And yes I pour it back in.

 

[DeputyDog95]

Just got one myself, love it.

Distilled or rodi is fine, both essentially the same thing.

You are correct 35ppt can also be used, if you can’t get down to 20c just check with rodi water or 35ppt (follow randys diy method to make calibration fluid.) then see how far off the line they are, this will let you know where the correct line is for 35ppt, could just mean you are a man above or below the 35ppt but it doesn’t need calibration very often, I’m sure a couple a days a year it’s down to 20c, the rest of the time just keep a bottle of your diy solution to check it’s still reading correctly. Remember to let the refractometer stand for at least a min when testing to allow the refractometer to temp adjust.

So I got my VeeGee a couple of days ago and finally opened it last night. My office was 76 degrees, and with distilled water sitting on the prism for a bit, it was reading around 2.5ppt. So I'm not sure if it was off because of the temp in my office or because it was just off from the factory. I would have thought it would have temp corrected as it's in the factory temp range. It was kind of odd though... they shipped it in a plastic bag, which contained the factory box and the device in the factory neoprene or whatever it is sleeve. I would have expected it to be in a box with padding containing the factory box, but the unit seems pretty sturdy and the little factory box wasn't damaged... Anyway, I loosened the set screw, adjusted the calibration ring to zero it out, and tightened the set screw again.

Is there a calculator somewhere online so I can ballpark how much it might be off calibrating at 76 degrees?

I could try cranking the air down, but with an office full of women, I don't think that will be well received LoL It'll be February before it gets that cold in FL

 

[Reef.]

So I got my VeeGee a couple of days ago and finally opened it last night. My office was 76 degrees, and with distilled water sitting on the prism for a bit, it was reading around 2.5ppt. So I'm not sure if it was off because of the temp in my office or because it was just off from the factory. I would have thought it would have temp corrected as it's in the factory temp range. It was kind of odd though... they shipped it in a plastic bag, which contained the factory box and the device in the factory neoprene or whatever it is sleeve. I would have expected it to be in a box with padding containing the factory box, but the unit seems pretty sturdy and the little factory box wasn't damaged... Anyway, I loosened the set screw, adjusted the calibration ring to zero it out, and tightened the set screw again.

Is there a calculator somewhere online so I can ballpark how much it might be off calibrating at 76 degrees?

I could try cranking the air down, but with an office full of women, I don't think that will be well received LoL It'll be February before it gets that cold in FL

This might help…

Salinity Correction Calculator

Aquarium calculator; Correct a relative specific gravity (sg) measurement taken with a non-temperature-correcting unit.

www.hamzasreef.com

To double check I would make a reference solution, buy some 0.01g scales for $20 3.65g of table salt and 96.35g of distilled or rodi water will make a 35ppt solution.

Got mine from Amazon, came in a cardboard Veegee box (cheap box) the device was in a black storage bag, the refractometer was also wrapped in cellophane.