permeameter
/ˌpəːmɪˈamɪtə/noun
1 Physics. An instrument for measuring the magnetic permeability of a substance or object.
2Chiefly Soil Science and Geology. An instrument for measuring the permeability of a substance, especially soil, to liquids or gases.
Origin
Late 19th century; earliest use found in Silvanus Thompson (1851–1916), physicist and electrical engineer. From permea- + -meter.