oleometer

from The Century Dictionary.

• noun An instrument for ascertaining the weight and purity of oil; an elæometer.
• noun An apparatus for determining the proportion of oil contained in seeds, nuts, pressed seed-cakes, and other materials. It is so contrived as to allow of a small quantity of a volatile solvent being used to extract the oil, being distilled back upon the material under treatment, and filtered through it a number of times in succession. See Soxhlet's extraction apparatus.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Chem.) An instrument for ascertaining the weight and purity of oil; an elaiometer.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun chemistry An instrument for determining the weight and purity of oil.