diaphanometer

== English == === Etymology === From Ancient Greek διαφανής (diaphanḗs, “transparent”) +‎ -meter. Compare diaphanous. === Noun === diaphanometer (plural diaphanometers) (archaic) An instrument for measuring the transparency of a fluid, such as a Secchi disk. === References === “diaphanometer”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.