Calibrating Refractometer?

[nightstalk]

Can i use my ro unit water to calibrate my portable refractometer?

 

[hatessushi]

yes, just make sure the temp is around what the instructions say it should be. I think 65 degree or so.

 

[nightstalk]

alright, thanks

 

[nightstalk]

Can i use bottled spring water to calibrate it?

 

[slugg3r]

No, Reverse Osmosis or Distilled water only. Bottled water would inaccurately calibrate.

 

[trainfever]

RO water should not be used either. You should really only use distilled water to calibrate your refractrometer. You can make your own by boiling tap water, preferably in a tea kettle. Hold a coffeee mug upside down over the steam. I use a coffee mug because it has a built in handle. When the steam condenses back into water, it will be distilled. You only need a few drops to calibrate your refractometer. You can easily get that much and then some by this method.

 

[joe 09]

imo the best way is to use a calibration fluid.you can calibrate the refactometer at 35ppt.you can buy it on line for about 4$.

 

[earlybird]

Don't they come with calibration fluid?

 

[gwh57]

Originally Posted by joe 09
imo the best way is to use a calibration fluid.you can calibrate the refactometer at 35ppt.you can buy it on line for about 4$.
This is the correct way to calibrate. It should be done at the point close to what you keep your tank. If you calibrate at "0" it may still be off at the higher readings.

 

[gmidd]

You just need distilled water.

 

[gwh57]

A number of people have discovered that their refractometers tested with tap or Ro and set to zero were way off when checking their tank water. The refractometer works with a slopping mirrow which is very often not mounted properly. The best method of calibration is to calibrate your refractometer at the same level on the scale that you want to test. Just because it reads correctly at zero is no indication that it will read correctly at 35ppt.