Salt meter - Enbunkei

Also known as a salinity meter, this instrument determines the amount of salt dissolved in aqueous solutions, seawater, etc., from measurements such as density, electrical conductivity, freezing point, boiling point, refractive index, osmotic pressure, and surface tension. Density is measured using a simple float scale. Measuring electrical conductivity is accurate and is the most commonly used method.

Source: Morikita Publishing "Chemical Dictionary (2nd Edition)" Information about the Chemical Dictionary 2nd Edition

塩量計ともいう．水溶液，海水などに溶存している塩分を，密度，電気伝導率，氷点，沸点，屈折率，浸透圧，表面張力などの測定値より求める機器．密度の測定は簡単なうきばかりを使用する．電気伝導率の測定が正確であり，もっとも多く用いられている．

出典　森北出版「化学辞典（第2版）」化学辞典 第2版について　情報