These instruments are called balances.
An aerometer is an instrument used to measure the mass and density of gases.
A balanced scale, which compares the mass of one object with that of a known quantity.
triple beam balance
Mass is measured against a standard by using an instrument called a balance.
An adequate balance.
This instrument is a balance.
This instrument is a balance.
A scale
This instrument is an adequate type of balance.
A balance
a scale
A scale
The mass spectrometer was used.
Mass is measured with weight, a graduated cylinder, and a scale.
A set of scales
mass
A balanced scale, which compares the mass of one object with that of a known quantity.