salometern.

/saˈlɒmɪtə/Etymology: < Latin sal salt or salum brine + -ometer comb. form.
the world > matter > chemistry > equipment or apparatus > [noun] > instruments > for measuring salinity
1860 M. F. Maury (ed. 8) ii. §102 The salometer confirms it.
This entry has not yet been fully updated (first published 1909; most recently modified version published online March 2018).