Captive Purity Refractometers

[bguile]

Are there any identifying marks or inscriptions that would identify "the real mccoy" from copycats? I need help as I think I may have been duped on Ebay. Check it out http://cgi.ebay.com/ws/eBayISAPI.dll...e=STRK:MEWN:IT
The device I received was in a blue case with styrofoam that didn't fit with a white "sampler" with a bulb, no instructions and was obviously in used condition. Let me know. I haven't heard from the guy after the first email for resolve and I've just sent the second one. I have pictures if needed.

Thanks.

[Ninong]

Are you the guy who paid the $45.00 for it?

You can find RHS-10ATC refractometers brand new for less than that online: http://www.premiumaquatics.com/Merch...ode=Hydrometer

Have you tried it out yet? Use either distilled water or good R.O./D.I. water and see if it reads zero. If not, adjust it to read zero with pure freshwater -- turn the screw. Then try it with tankwater (saltwater) to see what it reads.

To use it, simply clean the surface with freshwater and wipe it dry. Then place two or three drops of water on it and close the lid. Then hold it under very bright light (either sunlight or intense artificial lighting) while looking through the eyepiece end. Take the reading where the shaded portion's top edge crosses the scale. Since this is a sodium chloride refractometer, as opposed to a true seawater refractometer, you need to allow for that in your reading. If the refractomer reads 34 ppt, then you actually have ~33 ppt salinity. If it reads 36 ppt, then your true salinity is ~35 ppt. It will read about 1 ppt low because it is calibrated for NaCl, not seawater.

You do not need to make any adjustments for the temperature of the water because the ATC means it is "automatic temperature compensating."

[bguile]

Yep. That was me that bought it. Thanks for the instructions on how to use it. I still may pursue this thing just based on the principle that it's not what he said it is. We'll see. I did try to use it, but I'm glad I had another hydrometer to check it's reading. It's currently reading high and I almost changed my water make up based on it. Are all refractometers equipped with ATC?

[Ninong]

Yep. That was me that bought it. Thanks for the instructions on how to use it. I still may pursue this thing just based on the principle that it's not what he said it is. We'll see.

This is what he claimed it was according to his description: http://www.marinedepot.com/aquarium_...ter.asp?CartId=

I did try to use it, but I'm glad I had another hydrometer to check it's reading. It's currently reading high and I almost changed my water make up based on it.

If it was really brand new as he claimed, it would have been calibrated at the factory. I wouldn't assume that a hydrometer was correct compared against a properly calibrated refractometer.

Are all refractometers equipped with ATC?

Only those that have the initials "ATC" in their description. I haven't seen any that were not ATC but I'm sure they used to exist.

[bguile]

Yeah...that's what I was expecting to get, but not so. It looks more like the blue one you showed me but black. I'll have to check on the ATC thing. I remember seeing a gold label on the box but didn't really pay it much attention. I'll check it out when I get home.