Refractometer question

[babyduke]

I just received the refractometer which I ordered on line but it came with instruction written in Chinese. How do I make sure it's calibrated correctly?

[anthonys51]

mine came calibrated nd with a bottle of water. if you place a drop of that liquid on the glass part, it should read zero. if it does your good to go. if not adjust until it hits zero. make sure to clean off the glass with ro water each time you use it

[Cymonous]

I just received the refractometer which I ordered on line but it came with instruction written in Chinese. How do I make sure it's calibrated correctly?

I would contact the seller for proper instructions.

[Cymonous]

mine came calibrated nd with a bottle of water. if you place a drop of that liquid on the glass part, it should read zero. if it does your good to go. if not adjust until it hits zero. make sure to clean off the glass with ro water each time you use it

Not all of them come pre-calibrated. Actually, most don't. And most refractometers come with a calibration solution, not a bottle of water. The solution is a mix of saltwater at a certain salinity to help calibrate the refractometer.

[anthonys51]

not a refractometer expert. just telling you how mine came. yes it was called calb solution for mine too0. but in lamemens term, it was a little bottle of r/o water. because it read 0.0000. just giving my advice, thats all

[jason2459]

I would not calibrate any refractometer to 0 unless its all it can handle like the Milwaukee digital. These hand held optical refractometers particularly the cheap $30 brine ones that say they are saltwater should be calibrated to 35ppt or 1.0264. You can buy or make the proper calibration solution. Pinpoint makes one I've used for years.

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


http://www.reefkeeping.com/issues/2004-06/rhf/

http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=18717

[jason2459]

Also make note that they should recalibrated or at least checked for calibration often especially the cheap ones. I check once a month for calibration. When I had a few different cheap ones they would often drift a little each month and need calibration every time. I'm using a veegee/vital sine now and rarely does it need calibrated but I still check monthly.

[Sisterlimonpot]

Great advice, Never calibrate a refractometer to 0 unless what you're your testing is in fact 0. you always want to calibrate it to what you're testing it for.

I guarantee that most of the refactometers that are sold in this hobby aren't accurate if you calibrated it to 0.

35 ppm calibration fluid is easily attained from any online reef distributor. I highly recommend that you purchase a bottle and calibrate at least every 3 months.

[anthonys51]

what is the difference if its calibrated to zero or 35ppm. makes no sense to me, calibrated is calibrated plus stop buying cheap stuff, this isnt a hobby for the cheap imo. i spent good money on my refrac, i would advise you to do the same, because you get what you payin life

[jason2459]

what is the difference if its calibrated to zero or 35ppm. makes no sense to me, calibrated is calibrated plus stop buying cheap stuff, this isnt a hobby for the cheap imo. i spent good money on my refrac, i would advise you to do the same, because you get what you payin life
You generally try and calibrate as close to the target you want your sample to be to reduce any noise. The first link I posted is a great one especially for these cheaper brine refractometers. If calibrated to 0 they will be off at the level we're testing for. With my vital sine true seawater refractometers it is supposed to be possible to calibrate to 0 and still be accurate at 35ppt. I still do not do so. Just like when calibrating a pH probe I don't use a 4 reference solution but instead use 7 and 10 as what the levels I'm testing for are in that range.

[jason2459]

Plus did you read the OP? It's a cheap brine refractometer. Calibrating to 0 would be a mistake.

[Sisterlimonpot]

what is the difference if its calibrated to zero or 35ppm. makes no sense to me, calibrated is calibrated plus stop buying cheap stuff, this isnt a hobby for the cheap imo. i spent good money on my refrac, i would advise you to do the same, because you get what you payin life

When referring to a good refractometer, I'm thinking a lab grade one that will cost a few hundred to a few grand.

The ones offered in this hobby are far from those. You're relying on a screw to adjust the refracted light. this can vary greatly from 0 to 35ppm.

An easy way to conduct an experiment is to calibrate to 0 with distilled water, and then calibrate with 35 ppm. I would be shocked to learn that no adjustment would be required between the 2 calibrations.

[thegrun]

When referring to a good refractometer, I'm thinking a lab grade one that will cost a few hundred to a few grand.

The ones offered in this hobby are far from those. You're relying on a screw to adjust the refracted light. this can vary greatly from 0 to 35ppm.

An easy way to conduct an experiment is to calibrate to 0 with distilled water, and then calibrate with 35 ppm. I would be shocked to learn that no adjustment would be required between the 2 calibrations.

+1, without going into a lengthy explanation your refractometer can be off considerably if you calibrate it at 0.00, use 35ppt calibration fluid and get it right.

[jason2459]

+1, without going into a lengthy explanation your refractometer can be off considerably if you calibrate it at 0.00, use 35ppt calibration fluid and get it right.
Don't worry I posted a link to the article above that gets into the lengthy explanation.

[AmberLee]

You guys are lucky, I spent $100 on my refractometer, Reef Octopus brand I think it was. I have to calibrate mine before EVERY use, all it takes is for me to use it and then check it and hey it's out again :(

Think I need a new one considering I don't even know if when I calibrate it then use it, it stays calibrated during use...

[fishchef]

I just received the refractometer which I ordered on line but it came with instruction written in Chinese. How do I make sure it's calibrated correctly?

Hey, that one looks like mine. Have had it for 6 years and have calibrated it a couple of times. We use 35% calibration fluid to check. Has done the job. Really don't remember it being really cheap.

[tmz]

The scale you read is imperfect . The farther away from the measured solution the calibration point is, the greater the imperfection. So, it's best to calibrate nearest the level of the the solution you are measuring. Use a 54 mv solution and calibrate to 1.026/35ppt.

[Mom2jayden]

Is there any at home solution you can use to calibrate?

[scooter31707]

I might be doing this wrong as I was reading this tread, but I calibrated mine by using RO water which is 0ppm and adjusted it to 0. Never had a problem with it.

[jason2459]

Is there any at home solution you can use to calibrate?
Second link I posted above.

[jason2459]

I might be doing this wrong as I was reading this tread, but I calibrated mine by using RO water which is 0ppm and adjusted it to 0. Never had a problem with it.
First link I posted above and what I posted above and what tmz posted above.

[Sisterlimonpot]

Is there any at home solution you can use to calibrate?

Second link I posted above.

I remember that article, and at one time I was going to make my own calibration fluid from Randy's directions but for some reason I never got around to it.... I think because his steps were so exact that if I messed up even the slightest that I wouldn't get an accurate reading.

[jason2459]

I remember that article, and at one time I was going to make my own calibration fluid from Randy's directions but for some reason I never got around to it.... I think because his steps were so exact that if I messed up even the slightest that I wouldn't get an accurate reading.
Yep, same here and why I just pony up a few bucks and get the pinpoint solution.

[babyduke]

How do you read the salinity? My refractometer goes from 0-5-10-15-20-25-30. When I tested my tank water, it marked right in the middle of 0 to 5. Does that mean it's 1.025?:confused:

[jason2459]

How do you read the salinity? My refractometer goes from 0-5-10-15-20-25-30. When I tested my tank water, it marked right in the middle of 0 to 5. Does that mean it's 1.025?:confused:
Doesn't sound like a brine, saltwater, or seawater refractometers especially if it only goes to 30.

Should look something like this which is what I have and is very clear and easy to read compared to others I've tried like the d&d h2ocean and other cheap ones.

http://veegee.thomasnet.com/Asset/43036-WS.jpg

So when calibrating to targeting you should be on 35 on the right side or just above the 1.025 on the left.