How many letters does the top answer for “an instrument for ascertaining the specific gravity or density of a substance.” have?

The most common answer is densimeter (10 letters).

Crossword clue: an instrument for ascertaining the specific gravity or density of a substance.

1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

densimeter 10 letters web-def

An instrument for ascertaining the specific gravity or density of a substance.