Emanation Thermal Analysis ETA

Other methods of sample labeling are based on the introduction of the gas itself into the solids without use of the parent isotope. These methods 

All the preceding techniques yield products in which the incorporated gz is more or less stable. Inert gas atoms are situated in interstitial position in the crystal lattice. 

According to the theories of both the recoil and the diffusion processes (194), the release rate of the inert gas is given by 

When an inert gas is incorporated into a solid without its parent nuclide, the inert gas can be released by various diffusion processes, depending on the diffusion mechanisms. 

All the theoretical considerations are valid assuming that no chemical or physical transformations take place in the solid during heating. If a change in the structure or surface of the solid takes place, discontinuities occur in the ETA curve. 

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Emanation thermal analysis (ETA) involves the measurement of the release of inert (usually radioactive) gas from a solid sample, as a function of temperature. The rate of such gas release is essentially an indication of the changes taking place in the sample, and a comparison of ETA data with those of other thermal analysis techniques, particularly TGA and evolved gas analysis (EGA), provides information on the microstructure of the sample material. However, most of the solid samples studied by ETA are spiked ... 

The simultaneous measurement of emanation thermal analysis (ETA) with DTA has been described by Emmerich and Balek (77). ETA is further described in Section 14 of this chapter. 

The physical property measured and the corresponding thermal analysis technique are tabulated in Table 1.1 (3) and further elaborated on in Chapter 13. Notice that under the physical property of mass, thermogravimetry (TG), evolved gas detection (EGD), evolved gas analysis (EGA), emanation thermal analysis (ETA), thermoparticulate analysis, and others are included. Similar considerations can be included in the physical proparties of optical characteristics, electrical characteristics, magnetic characteristics, and so on. The definitions of each individual technique are given in the chapter in which they are discussed. A select number of the thermal analysis techniques are summarized in Table 1.2. Each technique is tabulated in terms of the parameter measured, a typical recorded data curve, the instrumentation needed, and the chapter in which it is described. 

The porous structure of the gels has been characterized by N2-adsorption, scanning electron microscopy (SEM), atomic force microscopy (AFM), and emanation thermal analysis (ETA) [16, 20]. The porosity of films was evaluated by refractive index measurements. 

Hirashima H, Imai H, Balek V (1998) Characterization of alumina gel catalysts by emanation thermal analysis (ETA). J Sol-Gel Sci Techn 19 399 02... 

Reduction in surface area and open porosity for a powdered sample is not readily measured by dilatometry. Density, BET adsorption isotherms, or emanation thermal analysis (ETA) are the applicable techniques. The latter is accomplished in a scanning temperature mode and, therefore, is capable of more rapidly identifying the significant temperature regimes. ETA involves substantial effort in sample preparation, however. A radioactive gas or its parent must be incorporated into the... 

Emanation thermal analysis is usually carried out in conjunction with other TA techniques, most notably DTA and EGA. In this context, ETA can be considered as a coupled TA technique. Carrier gas at a constant flow rate is used to carry the released gas from the sample to appropriate detectors—usually radioactive counting devices. In the case of desorbed radon, a scintillation counter is used, whereas Geiger counters are used for krypton, xenon, and argon. 

Sample products measured directly or indirectly on 1R Smoke evolution measured with phoiodetecior Dilatometry not always employed. ETA-DTA is generally called emanation thermal analysis... 

Thermally Stimulated Emanation Measurement (Emanation Thermal Analysis) radioactive gas released ETA... 

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