Seminars Products Services Downloads Clients Bios Contact

Density's Children: Introduction

By Walt Boyes

E-Zine January 2014

Density of liquids and slurries is one of the important parameters to measure, and doing it accurately is a difficult problem. Density is defined as the mass per unit volume of a liquid, and is usually expressed in “mass-over-volume” units like g/cc. For measurement purposes, we often want to know relative density rather than density itself. This measurement is the ratio of the mass of a volume of liquid to that of water at a specified temperature (usually 4°C), with the relative density of water defined as 1.0. This type of density uses units like SGU. Density measurements are temperature dependent, and temperature compensation is required for accurate measurement.

Density of liquids and slurries in tanks is relatively simple, since the fluid is static. You can weigh the liquid and measure the level. You can use a displacer type device and measure buoyancy. You can measure hydrostatic head using a pressure transducer. There are numerous alternatives.

The problem comes when you try to measure the density of a flowing fluid. Worse, let’s suppose that the fluid is a slurry. Now, suppose that the density of one or both slurry components is changing.

Click here to read "Wastewater Applications"

From Flow Control (September 2002)

ISSN 1538-5280

Spitzer and Boyes, LLC
Featured Consumer Guides
Coriolis Mass Flowmeters
Differential Pressure Flow Transmitters
Magnetic Flowmeters
Ultrasonic and Correlation Flowmeters
Vortex Shedding and Fluidic Flowmeters
Fieldbus Network Equip. for Process Control
Capacitance and Radar Contact Level Gauges
Non-Contact Level Gauges
pH and ORP Instrumentation

Order Information
Consumer Guides