Refractometer with no directions?

[Guest]

Hey all,

Just received my portable refractometer from Dr. Foster+Smith and it came with no directions.

This one http://www.drsfostersmith.com/produ...&Ntx=mode+matchallpartial&Np=1&pc=1&N=0&Nty=1

I now know how to use, however to calibrate I am confused. Just place distilled water on the prizm and make sure it is 0??

And distillled, so like Poland Spring is ok?

 

[RogerMcAllen]

I'm not a salty, but I inherited a refractometer from one. Put a few drops of distilled water on the prism (enought to cover the surface and close the thing down, set the "shadow line" to zero (should be with that tiny screwdriver and the thing at the top). Wipe the water away with a soft cloth. Put a few drops of salt water and repeat.

 

[Charlie]

Poland Sprigs water and distilled water are not the same thing. However, they did seem to produce similar results when calibrating my FS refractometer. I bought a gallon of distiled water at a CVS drug store for $1.50.

No adjustment was needed to re-calibrate my new unit. I keep the distilled water handy so that I can clean the salt water off the refractor after use before drying with a soft cloth.

It may pay to check calibration periodically but so far mine hasn't changed.

 

[roka64]

Both Roger and Charlie are correct. Use distilled water, about 3-4 drops, let sit for about 30 seconds (this really isn't important, because that refracto has temp correction, unless the water you are using is really hot or cold...).
If i remember correctly, mine was off a little bit and I had to use the screw driver. Just line up the two lines and you are ready to go.

 

[Tex]

Nice refractometer and you don't really need instructions. Use distilled water, I bought a gallon for about 70 cents, add 3 or 4 drops to the glass with the included dropper, close the lid and press gently to spread the water out evenly. Hold up to a light source and adjust the shadow line to zero. That's all there is to it. There is also a focus adjustment on the eye piece.

I bought the exact same model on eBay for about $22 plus shipping. The total was less than $30.

this one

 

[roka64]

One more thing. I got saltwater on the metal pin, because I flipped the arm to hard, it splashed the SW on the metal and now it is rusting...LOL! Just a little personal experience....

 

[Bearfan]

I thought the pin was stainless. I think mine is, years of use and no rust and I'm not ultra careful about getting saltwater on the pin.

 

[Guest]

Thanks everyone. I did it, and this thing seems great. Can't wait to use it!

 

[roka64]

I thought the pin was stainless.

I hear you, but stainless doesn't mean rust proof, at least in my experience. It is just more resistant. I would imagine, the movement and friction would rub off the stainless coating....But who knows....

 

[newfound77951]

stainless doesn't mean rust proof

yep, it doesn't....common misconception

and yes, Poland spring and RO/DI are not the same, but if the Poland spring water (or tap water, for that matter) didn't have a salinity of 0 I'd be very worried anyway.....

 

[woody]

I've got the same one and thought mine did not come with instructions either until I took all the foam out and it was in the lid. Wasn't much help then because I found all my answers right here.

 

[roka64]

mine did not come with instructions either until I took all the foam out and it was in the lid.

LOL! The same thing happened to me.

 

[Tex]

Funny thing. I'm an engineer with a few decades of experience with electronics and sophisticated testing and measurement equipment. Even had some college physics classes in light wave refraction way back when. However, until I started visiting this site, I had no idea there was an inexpensive, hand held refractometer made for aquarium use.

As mentioned, I have the refractometer being discussed in this thread and it is very cool. Interestingly enough, my Instant Ocean hydrometer is pretty dang accurate when compared to my refractometer.

 

[roka64]

My hydro was .00500 off, not much to us, but a lot to the fish.

 

[swjunkie]

woody and roka, I did the same thing they where in the top part of the lid behind the foam.

 

[Guest]

I cant BELIEVE THIS. LOL It was under the foam in the lid!!!!I was reading all your posts and I am thinking dont even tell me....Yep. I already claibrated it but they were there.

Thanks for the help