Density and concentration.

Density measurement is a parameter associated with the quality of a product, the concentration of a mixture, type of product, amount of solids, content ratio, contamination of a fluid, phase detection, dosage, saturation, among other characteristics of a fluid that is necessary to know in industrial processes.

Endress + Hauser has designed different measurement principles for density depending on the application, the process conditions and the required precision:

• Tuning fork vibronic measuring principle (general applications)
• Surface acoustic wave measurement principle (concentration or contamination monitoring)
• Coriolis measurement principle (high precision multivariable online measurement)
• Radiometric principle (extreme measurement conditions without process interruption)

Vibronic measurement principle (tuning fork)

A piezoelectric drive excites the Liquiphant's tuning fork to its resonant frequency. If the density of the liquid medium changes, the resonance frequency of the tuning fork also changes. The density of the medium has a direct impact on the resonance frequency of the tuning fork.

By storing specific properties of the medium and mathematical relationships in the system, the exact concentration of the medium can be calculated, for example.

PRODUCTS

Applications

• Density measurement of liquids in pipes or tanks in all industries
• Detection or differentiation of fluids (phase detection)
• Process conditions: temperature 0… 80 °C and maximum pressure 25 bar
• Calculation of concentration in a liquid in units of ° Brix, ° Baumé, ° API etc
• Approved in sanitary processes, corrosive fluids or explosive atmospheres
• Scalable multichannel system for up to 4 measurement points

Applications

• Measurement of Density / Concentration of liquids in pipes or tanks in a fixed or portable way
• Process conditions: temperature 0… 100 °C and maximum pressure 16 bar
• Detection of failure in filtering systems
• Monitoring of chemical processes, for example. particles in fluids
• Measurement of concentration in fluids, for example. glycol
• Monitoring of fluid contamination, e.g., leak detection in heat exchangers

Coriolis measurement principle

The Coriolis principle within a Coriolis flow sensor (which, according to its design, may have one or two internal measurement tubes). Fluid flows through measuring tubes that are constantly excited to oscillate at their resonant frequency. Any change in the density of the fluid produces a corresponding change in the resonance frequency of the entire vibratory system (measuring tube and fluid).

The resonant frequency, therefore, is a function of the density of the fluid: the higher the density, the lower the resonant frequency. In this way, by measuring the frequency of the system we can determine the density of the fluid.

PRODUCTS

Applications

• In line measurement of Density / Concentration of liquids in pipes from up to 1/24” to 16” in any industry
• Multivariable density, temperature and mass flow transmitter that allows concentration monitoring and dosing at the same time
• Process conditions: temperature from -200 to 350 °C and pressure up to 400 bar
• Calculation of concentration in liquid in units of ° Brix, ° Baumé, ° Alcohol, etc
• Approved for use in custody transfer systems

Applications

• Measurement of Density / Concentration of liquids in pipes, bypass or tanks without interrupting the process, mainly in the primary industry, mining, chemical and oil & gas
• No restrictions with process conditions: applicable extreme temperature conditions, high pressures or strong abrasion
• Measurement of solid concentration in mineral abrasive pulps and mining water
• Determination of product density in closed reactors at high pressure
• Measurement of solids concentration in drilling sludge