Refractometer Light Sources

VTek · Jan 19, 2016

Hey guys,

Just wondering if there were any differences between light sources that may alter a refractometer reading. When I use my refractomemter, I normally use the lights on my system (Radion XR15 Pro LED) as the light source as they are close, bight and convenient. Will this alter a reading that may come from the sun or outdoor lighting?

Cheers,

bobman · Jan 19, 2016

Good question and one I don't have an answer to but following along to see what others have to say.

bobman · Jan 19, 2016

Try using it on the radion then use ambient light by a window and see if you get different readings

TheEngineer · Jan 19, 2016

Huh.... That's an interesting question. I usually use sunlight just because I get a clearer reading. I haven't noticed a difference in reading between sources. I'm not sure which wavelength(s) are needed for the measurement.

bobman · Jan 19, 2016

Yeah not sure if color and intensity and possibly angle of light source would change the way the light refracts in the refractometer

TheEngineer · Jan 19, 2016

Lucky for us our friend @Randy Holmes-Farley wrote an article about this.

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

The refractometer is measuring the change in the speed of light as it comes through the saltwater. I'm going to say that for that reason the light source isn't important so long as you are not traveling at a speed close to the speed of light. That's my opinion. Let's see what an expert says.