A handy refractometer is an essential piece of equipment for any hobbyist and if you are looking for a great tool to take the guesswork out of measuring you salinity, you have to take a look at the Milwaukee Instruments MA887 Seawater Refractomer. This imposing looking piece of equipment is extremely accurate, simple to use and most of all — affordable.
The Milwaukee Instruments MA887 measures in three different scales: salinity (ppt), specific gravity and practical salinity unit (PSU). Running off a single 9V DC battery, the MA887 is accurate within 0.0001 on the specific gravity scale. The premise is simple, add a few drops of water into the optical measuring pan and hit “read” and within a second or two you have your reading.
As for calibrating the unit, all you need to do is place a few drops of distilled water on the pan and hit “zero” to calibrate it. The unit comes with a two year warranty and retails for around $120 and if you throw in the case, runs around $140. Considering an inexpensive visual refractometer start around $40, this is quite a bargain. Now if they only made this unit in a smaller size for the aquarist….we’re just saying.