What are the different methods for measuring liquid density in process applications?

Liquid density measurement methods: Coriolis (direct mass flow and density from vibration frequency shift - highly accurate, process temperature), vibrating tube/fork (resonant frequency depends on fluid density - accurate, temperature compensation needed), differential pressure (measures hydrostatic head difference - inferential, requires known height), nuclear/gamma (radiation absorption depends on density - non-contact, for difficult fluids), and hydrometer (floating device for spot checks). Selection factors: accuracy requirements, process conditions (temperature, pressure, fouling), installation constraints, and calibration needs. Coriolis is increasingly common due to accuracy and multi-measurement capability.