Noncontact

The magnetic regulators allow to synthesize in one module of the X-ray apparatus main cir-euit commutator, form converter, noncontact smooth ac voltage amplitude regulator, para-metrie stabilizer, ac supply filter, fimetional protection against the short-circuit in the X-ray tube and protection against emergencies in the control circuits. 

Sasaki N and Tsukada M 1999 Theory for the effect of the tip-surface interaction potentiai on atomic resoiution in forced vibration system of noncontact AFM Appl. Surf. Sc/. 140 339... 

Perez R, Payne M C, Stich i and Terakura K 1997 Roie of covaient tip-surface interactions in noncontact atomic force microscopy on reactive surfaces Phys. Rev. Lett. 78 678... 

Nakagiri N, Suzuki M, Okiguchi Kand Sugimura FI 1997 Site discrimination of adatoms in Si(111)-7 7 by noncontact atomic force microscopy Surf. Sc/. 375 L329... 

Fukui K, Onishi H and Iwasawa Y 1997 Atom-resolved image of the 7102(110) surface by noncontact atomic force microscopy Phys. Rev. Lett. 79 4202... 

Fig. 6. Van der Waals potential energy-distance curve showing regions of operation of contact, noncontact, and intermittent contact or tapping-mode afm...

This procedure offers the possibiUty of remote noncontact velocity measurement, where no probes disturb the flow. It is thus compatible for use with hot or corrosive gases. Commercial laser velocimeters have become weU-developed measurement tools. Examples of laser velocimetry include remote measurement of wind velocity, measurement of vortex air flow near the wing tips of large aircraft, and in vivo measurement of the velocity of blood flow. 

Rota.ry Lobe Pumps. Rotary lobe pumps are similar to gear pumps in principle. These pumps have an added advantage of noncontacting metal parts by use of external gears, which reduces the wear, but adds complexity. Low wear and improved shear characteristics make these pumps apphcable to the food industry, where cleanliness and absence of contamination are required. These pumps produce a strong pulsing flow that must be addressed. 

Noncontact Seals Noncontact seals are used extensively in gas... 

FIG. 21-49 Application of a noncontact inkjet printing system used for coding plastic bottles and corrugated fiberboard cartons. (VIDEOJET shown, couitesy of VIDEOJET Systems International, Inc., 1500 Mittal Blvd., Wood Dale, IL 60191-1073.)... 

Noncontacting Electrostatic Measurements These measurements are made by instruments that respond to the electric fields at their sensing electrodes. Gonsiderable care must be taken in the interpretation of the measurements. The three general types of devices are described as follows. 

The API Standard 670 covers the minimum requirements for noncontacting vibration in an axial-position monitoring system. 

Seals are very important and often critical components in turbomachinery, especially on high-pressure and high-speed equipment. This chapter covers the principal sealing systems used between the rotor and stator elements of turbomachinery. They fall into two main categories (1) noncontacting seals, and (2) face seals. 

These seals are used extensively in high-speed turbomachinery and have good mechanical reliability. They are not positive sealing. There are two types of noncontacting seals (or clearance seals) labyrinth seals and ring seals. 

The power loss can also be increased with seal contamination. The seal surfaces being noncontacting under dynamic conditions the power loss associated with dry gas seals is very small. The power loss for a 10-in. (254 mm) seal operating at 1000 psi (69 Bar) and 10,000 rpm is about 12-14 kW. With damage seal surfaces, these losses can be increased by 20-30%. 

Any existing instrumentation should be used if found to be adequate. While there are advantages in the use of noncontacting sensors built into... 

Noncontacting eddy-current vibration displacement probe adjacent to ... 

Electronics has, in fact, been a very fertile area for SEM application. The energy distribution of the SEs produced by a material in the SEM has been shown to shift linearly with the local potential of the surface. This phenomenon allows the SEM to be used in a noncontact way to measure voltages on the surfaces of semiconductor devices. This is accomplished using energy analysis of the SEs and by direedy measuring these energy shifts. The measurements can be made very rapidly so that circuit waveforms at panicular internal circuit nodes can be determined accurately. 

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