More on continuum mechanics

More on continuum mechanics

This includes mostly instruments which measure macroscopic properties of matter: In the fields of solid state physics; in condensed matter physics which considers solids, liquids and in-betweens exhibiting for example viscoelastic behavior. Furthermore, fluid mechanics, where liquids, gases, plasmas and in-betweens like supercritical fluids are studied.

Density

This refers to particle density of fluids and compact(ed) solids like crystals, in contrast to bulk density of grainy or porous solids.

• Aerometer liquids

• Dasymeter gases

• Gas collecting tube gases

• Hydrometer liquids

• Pycnometer liquids

• Resonant frequency and Damping Analyser (RFDA) solids

For the ranges of density-values see: Orders of magnitude (density)

Hardness of a solid

• Durometer

Shape and surface of a solid

• Holographic interferometer

• Laser produced speckle pattern analysed.

• Resonant frequency and Damping Analyser (RFDA)

• Tribometer

Deformation of condensed matter

• Strain gauge all below

Elasticity of a solid (elastic moduli)

• resonant frequency and Damping Analyser (RFDA), using the impulse excitation technique: A small mechanical impulse causes the sample to vibrate. The vibration depends on elastic properties, density, geometry and inner structures (lattice or fissures).

Plasticity of a solid

• Cam plastometer

• Plastometer

Granularity of a solid or of a suspension

• Grindometer

Viscosity of a fluid

• Rheometer

• Viscometer

Optical activity

• Polarimeter

Surface tension of liquids

• Tensiometer

Imaging technology

• Tomograph, device and method for non-destructive analysis of multiple measurements done on a geometric object, for producing 2- or 3-dimensional images, representing the inner structure of that geometric object.

• Wind tunnel

This section and the following sections include instruments from the wide field of Category:Materials science, materials science.

More on electric properties of condensed matter, gas

Capacitor Permittivity, relative static permittivity, (dielectric constant) or electric susceptibility

Such measurements also allow to access values of molecular dipoles.

Magnetic susceptibility or magnetization

• Gouy balance

For other methods see the section in the article about magnetic susceptibility.

See also the Category:Electric and magnetic fields in matter

Substance potential or chemical potential or molar Gibbs energy

Phase conversions like changes of aggregate state, chemical reactions or nuclear reactions transmuting substances, from reactants to products, or diffusion through membranes have an overall energy balance. Especially at constant pressure and constant temperature molar energy balances define the notion of a substance potential or chemical potential or molar Gibbs energy, which gives the energetic information about whether the process is possible or not - in a closed system.

Energy balances that include entropy consist of two parts: A balance that accounts for the changed entropy content of the substances. And another one that accounts for the energy freed or taken by that reaction itself, the Gibbs energy change. The sum of reaction energy and energy associated to the change of entropy content is also called enthalpy. Often the whole enthalpy is carried by entropy and thus measurable calorimetrically.

For standard conditions in chemical reactions either molar entropy content and molar Gibbs energy with respect to some chosen zero point are tabulated. Or molar entropy content and molar enthalpy with respect to some chosen zero are tabulated. (See Standard enthalpy change of formation and Standard molar entropy)

The substance potential of a redox reaction is usually determined electrochemically current-free using reversible cells.

• Redox electrode

Other values may be determined indirectly by calorimetry. Also by analyzing phase-diagrams.

See also the article on electrochemistry.