Paschen-Runge mounting

Figure 2.6 Basic design of direct reading on a Paschen-Runge mount with fixed optics on a Rowland circle used in simultaneous ICP-AES. (Reproduced by kind permission copyright 1999-2008, all rights reserved, PerkinElmer, Inc.)...

Fig. 19. Important optical mountings for optical spectrometers with a plane (A Ebert, B Czerny-Turner) and a concave (C Seya-Namioka, D Paschen-Runge) grating, m Mirror, se entrance slit, sa exit slit, gp plane grating, gc concave grating.

Figure 7.13 A Rowland circle polychromator. This configuration is called a Paschen-Runge mount. The source shown is an inductively coupled plasma, hut any of the electrical excitation sources can he substituted. Multiple photomultipler detectors are placed at the appropriate positions on the circumference of the circle to measure dispersed wavelengths. [From Boss and Fredeen, courtesy of PerkinElmer Inc. (www.perkinelmer.com).]...

The spectrometers used are adapted either for sequential or simultaneous multi-element measurements. Commonly used grating spectrometers in plasma AES include (i) spectrometers with the Paschen-Runge mount, (ii) echelle spectrometers, (iii) spectrometers with Ebert and Czerny-Turner mounts, (iv) spectrometers with Seya-Namioka mounts, and (v) double monochromators. Also Fourier transform spectrometers may be used in plasma AES. 

A Paschen-Runge mount is especially appropriate for multi-element... 

Another design of the Paschen-Runge mount for sequential measurements is shown in Figure 115. Here 255 fixed secondary slits with a regular spacing of 2 mm are mounted in the slit frame instead of the normal individual slits. Two movements are required to set the monochromator at a desired wavelength. First the carriage must be set to the specific exit slit, and then the entrance slit must be accurately moved to the desired spectral line. With... 

Fig. 12.28 Schematic diagram of a polychromator based on a Paschen—Runge mount and photomultiplier detection, (a) General optical set-up (b) side view and arrangement of the photomulitpliers.

FIGURE 4-12. Schematic diagram of the Paschen-Runge mounting for a concave grating. 

Simultaneous Spectrometers. Modem simultaneous spectrometers use photoelectric radiation detection rather than the photographic plates formerly used for qualitative and semi-quantitative analyses. Simultaneous photoelectric spectrometers mostly have a Paschen -Runge optical mounting. They have many exit slits and are especially suitable for rapid determinations of many elements in a constant, well-characterized matrix the achievable precision is high. However, the... 

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