Specimen holder

The method of supporting the specimen holder during the test... 

In a few special cases, the standard spool-type specimen holder is not apphcable and a suitable special test method must be devised to apply to the corrosion conditions being studied. 

It is occasionally desirable to expose corrosion-test specimens in operating equipment without the use of specimen holders of the type... 

FIG. 28-21 Sp ool-type specimen holder for use in 3-in-diameter or larger pipe. (Mantell, ed., Engineering Materials Handbook, McGraw-Hill, New York, 1958.)... 

Fig. 6-10 (right) Specimen holder for measuring current yield. 

Obhut, /. protection, care, obig, a. above, above-mentioned, foregoing. Objekt-abstand, m. (Micros.) working distance, -glas, n. (Micros.) slide, mount, -halter, m. (Micros.) specimen holder. 

Figure 7. Configuration of the materials durability test system 1, Zymark robot arm 2, Mettler balance 3, blotting station 4, capping station 5, specimen rack 6, water bath 7, block oven 8, vacuum oven 9, freezing chamber 10, NDT station 11, automated micrometer, and 12, washing station. O, specimen holder.

The cylindrical specimens (exposed area 3-10 cm ) were placed vertically in the cell. The specimen holder was provided with a collar that was filled with argon during testing. The crevice between the specimen holder and specimen was filled with a stream of argon to hold back solution from the crevice. However, distribution of the gas is critical and difficult to control satisfactorily. 

Figure 16. Electrode for pitting measurements with cylindrical specimens using the Avesta cell principle. The modification of the specimen holder is described in ASTM GS. Designed by Mathiesen and Maahn. (Reprinted from Ref. 73 by permission of the authors.)...

Specimen is in cylindrical form and together with its mounting is suspended in the solution. This specimen holder can easily be introduced in the Avesta cell by covering the hole in the bottom and by making slight changes in the top of the cell. 

The electron diffraction chamber used in SA resembles an electron microscope. However, it has simplified electron optics which consists of two condenser lenses for collimating the electron beam (upper) and for focusing on the screen (lower) (Fig. 2). The specimen holder and the sizes of the... 

Figure 2. The scheme of the electron diffraction camera EMR-102 (produced by SELMI Ltd. (Sumy, Ukraine). 1 - Electron gun, 2-Two condenser lenses, 3 - Specimen holder, 4 -Chamber, 5 - Optical microscope, 6- Tubule, 7 - Photo-chamber.

To determine PCT cnrve by volnmetric method at first we have to know mass of analyzed powder (hydride or pnre metal). The typical mass of powder used in volumetric method is in a range 50-500 mg and depends on (reactor volume with volume of connecting pipes, valves, and transdncer). After the mass measurement, the powder is loaded into specimen holder and then it is placed in the Sieverts apparatus reactor. To prevent any oxidation and for safety reason the system must be purged a few times by argon and then evacnated. However, one must be careful how much powder is appropriate for the absorption/desorption volume of a Sieverts-type apparatus. 

Fig. 21.6 Representative wide angle camera and specimen holder arrangement.

Place the specimen holder with the sample in place. 

The construction of DTA apparatus is simple and consists of a furnace, differential thermocouple, temperature thermocouple, specimen holders, temperature programmer and recorder. The schematic of a typical DTA apparatus is shown in Figure 3.5. 

After polishing, the specimens were stored in a desiccator until testing. Once mounted in the specimen holder, the specimen was scanned for fibers that were spaced a minimum of 2 /rm and a maximum of one half of their diameter from the nearest neighbor. Matrix conditions near the fiber of interest were also considered. Fibers near voids, cracks, or surface damage or those fibers that showed a pre-existing interfacial crack were rejected. Once a suitable fiber end was located, its diameter and distance to the nearest neighbor were entered for data reduction purposes. 

Fig. 2.47 View of DMA specimen holder, red arrow indicates specimen and blue arrow indicates environmental chamber that closes over the specimen grips during testing...

---