refractometer use

[treesprite]

Please tell me what holding, handling, and viewing practices will get me a clear line every time. Thanks.

[kjamaya]

I use my metal halide light to get a clear view. Is it blurry or cloudy?

[gmerek2]

every time I take it out of the case it knocks the focus out of wack. My LEDs give a bad view so I have to turn a light on.

[Origami]

I put 3 to 5 drops of water on the viewing stage before flipping the cover glass over the top. Make sure that there aren't any trapped air bubbles under the plate and that the plate is completely flat against the refractometer body (so that the water sandwiched inside is an even thickness). Then, just point it up towards a bright light source (I use a fluorescent bulb on the ceiling). You should get a clean, clear shadow line to help you take the measurement.

[zygote2k]

I test the water 3 times with a refractometer then average the results.

[YHSublime]

I do like Tom, in that I use the florescent that we have in the kitchen. My water mixing station is in a closet, so when I test my new made saltwater, I have been known to walk around like a drunken pirate trying to get the best light to read in. Now I usually just go into the kitchen. I also add a liberal amount of water to the glass pane. I don't know if that is good practice or not, but everything seems to be alive.

[flowerseller]

I add a couple drops of tank water from my finger and then aim towards a light source until I get a clear reading.

Don't press the water out from between the glass and the flap when you shut it.

 

The "focus" does not change the reading, just the clarity of the scale.

[jaddc]

I test the water 3 times with a refractometer then average the results.

This.

[Origami]

I test the water 3 times with a refractometer then average the results.

...to six decimal places. Bring a calculator.

[sachabballi reef]

for my old eyes the best light for me is the natural light...so I take it to the window whenever possible

[AlanM]

I have to take off my glasses to see it well through the eyehole.  Also, I calibrate mine every time with 35ppt solution.

[zygote2k]

nearest thousandth is fine. It's not like we're breeding whales.

[flowerseller]

I test the water 3 times with a refractometer then average the results.

 

Are you taking the test water from 3 different areas of the tank?

[Origami]

I normally take only one measurement, but I'll tell you what I do:  I use a pipette and draw my water from several inches below the water line in an area with some decent flow. I also flush the pipette four or five times to make sure tha any salt residue is gone. Then, after the test, I wipe the refractometer down to keep it clean.

[sachabballi reef]

I normally take only one measurement, but I'll tell you what I do:  I use a pipette and draw my water from several inches below the water line in an area with some decent flow. I also flush the pipette four or five times to make sure tha any salt residue is gone. Then, after the test, I wipe the refractometer down to keep it clean.

+1

[Jim Mc]

I do like the others but maybe I am missing part of your question.  If it is blurry turn the focus which is normally the end where the eye hole is.

[jaddc]

I'll add some more science.

 

If the scale is clear, then the device is in focus.

 

If you want a clear sharp refraction line, there are two thing to consider:

1) The film of saltwater must be thin. I load a few drops on the glass surface and press down on the lid, squeezing out the excess. Check that there are no air bubbles. While reading I press down on the lid (from the edges) and the line sharpens.

2) Light source. Point directly at the brightest light you can find. The brighter the light, the sharper the line will appear.

[sen5241b]

1+ you need strong light