PRECISION METROLOGY

Fig. 6.3. Precision metrology surface inspection of the first-wall component of a fusion reactor.

TV cameras have been developed for a wide variety of hostile environments and are applicable to refueling. They represent an dtemative optical meftiod but will not provide the clarity of view of precision metrology. Specialized TV cameras such as fiberscopes have been developed with high radiation resistance and enable the electronics to be positioned in cooled low-radiation zones. 

Kugel, H. W., D. Loesser, A. L. Roquemore, M. M. Menon, and R. E. Barry, 2001, Precision Metrology of NSTX Surfaces Using Coherent Laser Radar Ranging, Review of Scientific Instruments, 72(1), 533-536 (January). 

To relate optical frequencies to the cesium time standard remains a very important issue in precision metrology. In this context the development of the opticai-frequency-comb technique using mode-locked lasers has been very important [9.400]. 

The evaluation of metrological characteristics of the technique, perfonued with minerals of different composition, showed that technique developed for reliability and precision satisfies the requirements offered for quantitative determinations, category II. The detection limits are acceptable for solving the problems posed and amount to 0.1 - 0.4 wt. %, depending on the element analyzed. 

Application of IP and NCS in conjunction with specification tolerance limits enables to substantiate acceptance criteria for linear regression metrological characteristics (residual standard deviation, correlation coefficient, y-intercept), accuracy and repeatability. Acceptance criteria for impurity influence (in spectrophotometric assay), solution stability and intermediate precision are substantiated as well. 

The analysis was performed by SRXRF at the XRF beam-line of VEPP-3, Institute of Nuclear Physics, Novosibirsk, Russia. For accuracy control the International Certified Reference Materials were used. There were obtained all metrological characteristics, namely precision, accuracy and lower limits of detections. 

A. A. Miehelson (Chicago) optical precision instruments and the spectroscopic and metrological investigations carried out with their aid. 

Group delay (III.6) Group delay encodes information on the source position. This observable can be calibrated using reference stars or suitable metrology. It is used for high precision astrometry. 

Fig. 16 Representative data from the surface wrinkling metrology, demonstrating the unprecedented range of moduli and the precision that the methodology unlocks a modulus of a thickness gradient library of PS (reproduced with permission from [72]) b modulus as a function of composition for P(S-I-S) triblock copolymer blends c modulus as a function of thickness for ultrathin PS films (reproduced with permission from [74]). The lines are meant to guide the eye and the error bars represent one standard deviation of the data, which is taken as the experimental uncertainty of the measurement...

This experimental development was matched by rapid theoretical progress, and the comparison and interplay between theory and experiment has been important in the field of metrology, leading to higher precision in the determination of the fundamental constants. We feel that now is a good time to review modern bound state theory. The theory of hydrogenic bound states is widely described in the literature. The basics of nonrelativistic theory are contained in any textbook on quantum mechanics, and the relativistic Dirac equation and the Lamb shift are discussed in any textbook on quantum electrodynamics and quantum field theory. An excellent source for the early results is the classic book by Bethe and Salpeter [6]. A number of excellent reviews contain more recent theoretical results, and a representative, but far from exhaustive, list of these reviews includes [7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17]. 

Albert Michelson developed the interferometer about 1880 and conducted the Michelson-Morley experiment in 1887, in which it was found that the speed of light is independent of the motion of the source and the observer, this crucial experiment led Einstein to the theory of relativity. Michelson also used the interferometer to create the predecessor of today s length standard based on the wavelength of light. He received the Nobel Prize in 1907 for precision optical instruments and the spectroscopic and metrological investigations carried out with their aid. ... 

The Slovak Institute of Metrology (SMU) has recently rebuilt its high-precision coulometric equipment to be used as a national standard for amount of substance measurements. Its main purpose is certification of primary reference materials of composition with directly determined main component. These primary reference materials can be subsequently used for disseminating traceability into different chemical measurements. 

National traceability or dissemination structures, internationally linked via comparison measurements under the CIPM Mutual Recognition Arrangement, are beginning to play a central role in establishing trace-ability of chemical measurements in practice. Reference materials are the most important transfer standards for disseminating traceability (more precisely the units of measurement) to the user level. Availability of certified reference materials with evidence of their metrological quality is, however, very limited. Great efforts are necessary to improve this situation. 

Precision frequency metrology is now compatible for the search of a variation of the constants [38]. A new generation of frequency chains [8] allows to easily do two kind of frequency measurements which were hardly available previously ... 

Fundamental physical constants are universal and their values are needed for different problems of physics and metrology, far beyond the study of simple atoms. That makes the precision physics of simple atoms a subject of a general physical interest. The determination of constants is a necessary and important part of most of the so-called precision test of the QED and bound state QED and that makes the precision physics of simple atoms an important field of a general interest. 

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