Dilatometry principle

This monograph provides an introduction to scanning ther-moanalytical techniques such as differential thermal analysis (DTA), differential scanning calorimetry (DSC), dilatometry, and thermogravimetric analysis (TG). Elevated temperature pyrometry, as well as thermal conductivity/diffusivity and glass viscosity measurement techniques, described in later chapters, round out the topics related to thermal analysis. Ceramic materials are used predominantly as examples, yet the principles developed should be general to all materials. 

An interferometer can be used to very accurately measure the thermal expansion of solids. Although not utilized commercially to the level of dilatometry, NIST standard materials, which are in turn used to calibrate dilatometers, have had their expansion characteristics determined using interferometry. In fact, the formal definition of the meter is based on interferometric measurements. The operation of the device is based on the principle of interference of monochromatic light. The fundamental relations between wavelength and distance will first... 

The theory and principles of dilatometry are particularly well described by Hannewijk et al. (1964). 

The rates of change (slopes of the curves) of many important properties (such as the refractive index, surface tension, and gas permeabilities) as a function of temperature, the value of the dielectric constant, and many other optical and electrical properties, often change considerably at Tg. These changes enable the measurement of Tg by using techniques such as refractometry and dielectric relaxation spectroscopy. Refractometry provides results which are similar to those obtained from dilatometry, because of the correlation between the rates of change of the specific volume and of the refractive index with temperature. Dielectric relaxation spectroscopy is based on general physical principles which are similar to those in dynamic mechanical spectroscopy, the main difference being in its use of an electrical rather than a mechanical stimulus. 

Swayze 1942 described three principles for measuring chemical shrinkage, which are called dilatometry, gravimetry and pycnometry ... 

As far as the author knows, Le Chatelier (1900) was the first to report measurements of chemical shrinkage in cement paste he used dilatometry. This measuring principle is used in the ASTM standard for testing early-age hydration, ASTM C1608 (2012), Test method for chemical shrinkage... 

Principle and procedure of measuring (including accuracy of balance (gravimetry) or pipettes (dilatometry)... 

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