Please quote the availability of your most competitive price and best delivery time FOB for waterproof salinity tester. A waterproof salinity tester (or salinometer) measures the salt content (salinity) in water, usually displayed in parts per thousand (ppt) or Practical Salinity Units (PSU). These testers often use an amperometric conductivity probe, which measures the electrical conductivity of the water, with higher salinity leading to increased conductivity. They are designed to be waterproof, and some even float, making them suitable for use in various water environments like saltwater aquariums, pools, and ponds.