Refractometer Calibration Fluid

[Thisseemsfishy]

Is there a good solution to calibrate my refractometer with besides the normal calibration fluid? I've read that RO or distilled water is not exact, so is there anything else to use?

 

[KafudaFish]

look around the chemistry archives.
I believe that Randy was a DIY solution.

 

[DevilBoy]

This is what i use.

http://www.bulkreefsupply.com/store/pinpointr-salinity-calibration-fluid.html

 

[thegrun]

+1, I just purchase mine. Most LFS carry it.

 

[IslandCrow]

Why are you opposed to using normal calibration fluid? Randy's DIY will work fine, but you need to make sure your measurements are very precise. Calibration fluid isn't exactly expensive, though.

 

[Thisseemsfishy]

Why are you opposed to using normal calibration fluid? Randy's DIY will work fine, but you need to make sure your measurements are very precise. Calibration fluid isn't exactly expensive, though.

Only because our LFS 's do not carry it and I thought I might have things around that I could make it with.

I guess I'll throw it in with my salt order in a few weeks. Thanks guys

 

[stevedola]

thats your best bet. always nice to have it handy and it never runs out...buy it once and youre all set. I can see what youre saying though, you would pay more for shipping than the actual cost of the item at most online retailers.

 

[dixiedog]

Can someone explain why using RO isn't good enough? That's all I've ever done.

How far off could my calibration be?

 

[disc1]

Can someone explain why using RO isn't good enough? That's all I've ever done.

How far off could my calibration be?

It depends on what type of refractometer you have. Any time you are calibrating a scale, you need two points. One to set the zero point and another to set the slope of the line. We can only make one adjustment to a refrac because you can't change the angle of the prizm. So we only get one point of calibration. It is therefore best to have that single point be the same as the point you want to read accurately. The refrac will be off by more and more the further away from that calibration point you go. So you can either set 35ppt and 0 will be off, or you can set 0 and 35ppt will be off.

 

[hogben]

Nice explanation!

 

[organism]

Can someone explain why using RO isn't good enough? That's all I've ever done.

How far off could my calibration be?

Mine ended up being off by .004 with ro/di, calibration fluid is well worth the investment.

 

[z3r0ko0l]

This is what i use.

http://www.bulkreefsupply.com/store/pinpointr-salinity-calibration-fluid.html

+1

Same here. Its cheap, lasts a long time, and works. Follow the instructions and your golden.

 

[Chris Lakies]

Sybon is good.

http://premiumaquatics.com/store/merchant.mvc?Screen=PROD&Store_Code=PA&Product_Code=REFRACT-SF&Category_Code=

 

[dixiedog]

Mine ended up being off by .004 with ro/di, calibration fluid is well worth the investment.

So if your actual SG was 1.026 (for instance), you might read 1.030, or 1.022?

I just want to make sure I understand how much I might be off by.

 

[allsps40]

I use Pin Point, works great and accurate. Make sure the fluid and refractometer are 76 degrees before calibrating.

 

[Thisseemsfishy]

Thanks to everyone! All ideas and help is greatly appreciated

 

[disc1]

So if your actual SG was 1.026 (for instance), you might read 1.030, or 1.022?

I just want to make sure I understand how much I might be off by.

Yessir. You got it.

 

[Lynnmw1208]

This is what i use.

http://www.bulkreefsupply.com/store/pinpointr-salinity-calibration-fluid.html

+1 I got this with the refractometer I bought at BRS. LOVE it so easy!