Is my Refractometer messed up?

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mrg02d

Aquarium Advice FINatic
Joined
May 30, 2009
Messages
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Location
tallahassee, florida
Hello all,
I have been having trouble with my refractometer for months now and finally decided to give in and ask for help. :)

I have a SmartReef refractometer from TBaquatics. There are two problems I am having:
1-Calibration wont EVER hold. Basically, it has a screw and some nut that you use to lock the calibration with. I use 35ppt fluid and adjust the line to the right mark on the screen. I then lock the nut down so the set screw cant move. I check again that the line hasnt moved, clean the prism and plastic screen with DI water, dry, and then attempt to check my tanks salinity. More often than not, I am alarmed at either way too high or way too low salinity. I check the refractometer with some more 35ppt fluid and find that the dang line has wondered off signitficantly even though the screw cant move! If I try enough, I can get an accurate reading on tank water and PWC water.

2-More often than not, the line is blury or there are multiple lines. This makes the reading useless! If I push down hard on the plastic screen that goes over the prism, the line will sometimes clean up. Letting go causes chaos again!

Help! I am going crazy! This was a $50.00 refractometer! It shouldnt be having these problems, right? I am about to go back to my hydromter as at least its consistent.

Ideas?Tips? Anyone have these issues before? This thing was a problem from day one but it was my first one so I figured I was doing something wrong.

Thanks!
Matt
 
Wow matt, I'm sorry to hear of your problem but I can't put my finger on the problem. For the heck of it would you try to calibrate with just R/O water so you can rule out a diffective solution?
 
2-More often than not, the line is blury or there are multiple lines.
Can you focus it? By turning the rubber eye piece you can make that line crystal clear. Maybe that's the whole problem?
 
Hey guys, I am actually on my 2nd bottle of 35ppt fluid (new brand) and still the same trouble. The eyepiece only focuses the numbers on the screen rather than the line created by the blue/white difference.

Im wondering if there is some way to adjust the prism and cause it to move? Maybe its loose, or maybe something else is loose. Im at my wits end with the thing. :-(

Matt
 
Besides focusing by turning the eye piece there should be a knob that is on the front that you use for calibration. It's a knob with a nut that you use to lock your calibration so it stays where you want it. If not can you take a picture of it.
 
TC, Matt stated that he locks down the calibration nut. It would seem there is something wrong with this unit.

Matt, have you contacted Brian at TB aquatics about this unit?

How much fluid are you placing on the lens before closing the cover?
Do you wait 30 seconds or so for the temperature to stabilize?

The eyepiece not only clears the numbers, but a slight change can make the line sharp vs. a bit blurry. You really need to use enough water, wait the 30 seconds or so AND use BRIGHT LIGHT. Try loading it up and going outside to check it in the sunlight. Does that clear up what you are seeing?

Last resort, have you had your eyes checked recently? :)
 
Just a shot in the dark here but any bubbles can cause problems as well.

Like was stated above, I have to go outside to get a clear line. Bathroom lights just don't work well.

But your statement of you recheck it with the same fluid and it is off again causes concern about the unit itself.
 
mrg, Cmor has the best solution and that is to contact the place you bought it from and see if they will exchange it for you.
ps: Thanks for the heads up, Cmor...I should read the whole link...
 
Hey guys, thanks for all the tips! I will try out the sunlight later today when the clouds clear up.

Never been dropped. No bubbles. I use three drops. I have tried lots of water and very little water. The more water, the more the plastic guard thing moves and causes instability.

I didnt want to bother TBaquatics so long after buying the thing. (I got it in the spring).

Matt
 
I have found that more than 3 drops of water placed on the glass doesn't really impact it when you put a little pressure on the cover to seat it.
I have the Milwaukee brand and it is very consistent. Your post reminded me that it was time recalibrate mine, thanks.
 
I have found that more than 3 drops of water placed on the glass doesn't really impact it when you put a little pressure on the cover to seat it.
I have the Milwaukee brand and it is very consistent. Your post reminded me that it was time recalibrate mine, thanks.


Hmmm...So you are saying to try using more water and pressing down on the cover some?

Still waiting for that sun to shine through the clouds! "Rain rain, go away...."

Matt
 
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