Using the Dupla Marin hydrometer as a hardware salinity reference

The Dupla Marin high resolution Hydrometer came along at a time when we are really becoming quite critical about salinity measurement. This large, oversize hydrometer is specially designed to measure seawater salinity at 25C/77F but only between 33 and 38 parts…

Accuprobe Hydrometers from Aquarium Solutions are individually calibrated

The AccuProbe Hydrometer and Mini Hydrometer are an interesting take on the old plastic specific gravity tester. At first glance the full size AccuProbe looks more or less like the Coralite Deep Six hydrometer which was introduced over a decade…

Milwaukee Instruments MA887 Seawater Refractomer is useful, accurate and affordable

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…

Marine Salt Testa from Trans Instruments is a waterproof salinity pen

The Marine Salt Testa is a three-in-one electronic testing pen that measures conductivity, temperature and salinity. And it floats. The new testing device from Trans Instruments can easily be calibrated, it is water proof and has a replaceable electrode tip.…

D-D’s seawater refractometer might be the only one scaled for seawater, not saltwater

As far as we can tell, D-D’s Seawater refractometer is perhaps the ever such device that is scaled and calibrated for use with seawater. “That’s crazy talk” you say as you peer upon your aquarium refractometer which was likely designed…

C-scope refractometer from JBJ can be read by seeing impaired

JBJ C-scope refractometers is the newest addition to JBJ’s line of products and it aims to at least make the dern thing easier to read. In addition to the usual automatic temperature compensation, easy calibration and a rugged build, the…