Dictionary.com
definitions

aerometer

[ai-rom-i-ter]
noun
  1. an instrument for determining the weight, density, etc., of air or other gases.

Origin of aerometer

First recorded in 1785–95; aero- + -meter
Related formsaer·o·met·ric [air-uh-me-trik] /ˌɛər əˈmɛ trɪk/, adjectiveaer·om·e·try [ai-rom-i-tree] /ɛəˈrɒm ɪ tri/, noun
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for aerometer

aerometer

noun
  1. an instrument for determining the mass or density of a gas, esp air
Derived Formsaerometric (ˌɛərəˈmɛtrɪk), adjective
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012