Tips On Reading Refractometer?

[bevo5]

This is a dumb simple one - but lately my refractometer has been giving me all sorts of trouble. I can test the same water twice in a row and get different results....but then I try to zero it out with pure RODI and it reads perfectly zero.

And when I hold it up to a light I've started getting two white lines. One kind of faint white line and then the main break between dark and light - which is a bit blurry most of the time anyway.

I've got the APEX conductivity probe hooked up but that thing is notoriously off....

So - any good tips on getting this thing to read better or should I just buy a new one?

 

[redfishbluefish]

First off, calibrate your refractometer with 53mS calibration fluid....not RO/DI water.

Secondly, the little hinged door needs to swing freely. If it doesn't swing freely, and "close" all the way, you will get a false reading. What I do to lubricate the hinges on the little door, is to shoot a little WD40 into an aperitif glass and then using a toothpick, I dab the WD40 on the hinge parts, swinging them back and forth until that move freely.

The last thing is always use the same light source to read your refractometer. I prefer using sunlight when calibrating and reading newly mixed saltwater.

Hope this helps.

 

[bevo5]

Hey thanks. That's a great tip on the door. I noticed the other day it has been sticking quite a bit. That's gotta be part of the problem.