Calibrate refractometer

[madlynb]

How do you calibrate a portable :?: refractometer?

 

[ccCapt]

Buy a bottle of Pinpoint calibration fluid. Cots about $10 and will calibrate to 35 ppt or 1.026 SG. You can use distilled or RO/DI water to calibrate to 0, but that doesn't mean it will properly read 35 ppt.

 

[mblack]

as above or get someone who has calibrated their refractometer properly to make up some saltwater then calibrate yours using that water.