Wedge-shaped samples

It is sometimes desirable to eliminate interference bands from transmission spectra this is particularly true in the measurement of absorption spectra (a as a function of wavelength), where interference bands can be a nuisance. If 8h X/An, a condition that can be achieved by using a wedge-shaped sample, for example, then the observed transmittance is given by (2.76). 

Figure 2.7 Video footage of the quenching process for the CS wave in a wedge-shaped sample, obtained by using a conventional video camera (left) and IR-thermal video technique. (Adapted from Ref [16] with permission from FizMatLit.)...

The use of wedge-shaped samples is an appropriate testing method to study the influence of geometry effects on the material degradation mechanism by high-temperature corrosion. 

This procedure has been utihzed to determine metal cations and anions in water sample [48,50,51], titanium in high-speed steel at a concentration level of 25 3 mg/g [22], heavy metals (20 to 400 mg/1) in electroplating waste waters [25], copper and nickel (5 mg/1) in metal electroplating baths on wedge-shaped plates [44], copper, lead, cadmium, or mercury in vegetable juices [29], and nickel (1 to 3.8 mg/1) in electroplating waste water of lock industries [42,47]. 

IR spectrometers have the same components as UY/visible, except the materials need to be specially selected for their transmission properties in the IR (e.g., NaCl prisms for the monochromators). The radiation source is simply an inert substance heated to about 1500 °C (e.g., the Nernst glower, which uses a cylinder composed of rare earth oxides). Detection is usually by a thermal detector, such as a simple thermocouple, or some similar device. Two-beam system instruments often work on the null principle, in which the power of the reference beam is mechanically attenuated by the gradual insertion of a wedge-shaped absorber inserted into the beam, until it matches the power in the sample beam. In a simple ( flatbed ) system with a chart recorder, the movement of the mechanical attenuator is directly linked to the chart recorder. The output spectrum is essentially a record of the degree of... 

In this test, a wedge-shaped expl sample is confined on the bottom by a one-inch-thick brass plate and on the sides by -inch-thick steel bars (Fig 1)... 

Majowicz Jacobs (Ref 1) and Campbell et al (Ref 2) first used the wedge test to study shock initiation of solid expls. The test is named for the wedge-shaped expl sample that is shocked by a booster-and-attenuator system as shown in Fig 1... 

A correct alternative to the one-dimensional cross-stream slice with parallel sides is a cutter (sampling tool) that rotates around an axis in a circular fashion. In such a case, the cutter must have a radial shape, that is, it must be wedge-shaped, with the cutter edges converging towards the axis of rotation (Fig. 4). This design ensures that material on the outside of the arc, where the cutter moves faster, has the same chance of being in the sample as material near the center, where the cutter moves more slowly. 

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