High: resolution

Resolution traduces the ability of an analyzer to separate ions it correlates with the precision of the measure of m/z ratios. The analyzers are generally separated into two categories low and high resolution. The first category groups quadrupoles and ion traps, the second includes ICR, TOP analyzers equipped with electrostatic reflectors, and devices that combine a magnetic sector with an electric sector. 

One generally speaks of high resolution when an analyzer measures the m/z ratios of the ions with a precision of at least four decimals. High resolution allows distinction of ions known as isobars that is, they possess the same m/z ratios even though their chemical formulas are different. For instance, the C5Hi40N and C5Hi6N2 ions are isobars with m/z ratios of 104. High resolution allows their separation because the first s m/z ratio is 104.10699 and the second s is 104.13080. 

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All have molecular weights of 226 to the nearest integer (C = 12, H = 1, S = 32), but the exact molecular weights differ slightly. A resolution of 2500 is necessary to separate molecules 1, 2 and 3 but 75,000 is required to separate molecule 4 from molecule 3 which explains why high resolution mass spectrometers are sdiiglit. 

Interest in this method has decreased since advances made in gas chromatography using high-resolution capillary columns (see article 3.3.3.) now enable complete identification by individual chemical component with equipment less expensive than mass spectrometry. 

Brown, J.K. and W.R. Ladner Jr (1960), Distribution in coallike materials by high-resolution nuclear magnetic resonance spectroscopy . Fuel, Vol. 39, p. 87. 

Fisher, I.P. and P. Fisher (1974), Analysis of high boiling petroleum streams by high resolution mass spectrometry . Talanta, Vol. 21, p. 867. 

To derive a reservoir geological model various methods and techniques are employed mainly the analysis of core material, wireline logs, high resolution seismic and outcrop studies. These data gathering techniques are further discussed in Sections 5.3 and 2.2. 

Up-to-day reliability requirements as applied to NPP strength maintenance govern development of new generation of computerized systems for in-service inspection. These systems in parallel with capabilities of ordinary ultrasonic techniques allow to reconstruct high resolution image of inner flaw and increase available amount of information. 

Hammersberg, P., Techniques for the determination of the optimal performance of high resolution computerised tomography, in Department of Mechanical Engineering. 1997, Linkbping. p. 173. 

The systems of such type have been developed of all last 10 years. We shall bring some characteristics of one of the last development within the framework of European BRITE project, carried out in LETT This 3D cone-beam tomograph is referred to as EVA Bench or Equipment for Voludensimetry Analysis. It is oriented on NDT of industrial products from ceramics and other composites. One of the main task of this tomograph is achievement of high resolution at study of whole internal volume of researched object. For test sample of the size 10mm spatial resolution in 50mm was obtained [14]. 

The divergent shape of the beam provides facilities for magnification in the distances of the source to detector and of the sources to the axis of rotation, which used in conjunction with a microfocus x-ray source opens the way to high resolution. 

We need to point out that, if the wavelengths of laser radiation are less than the size of typical structures on the optical element, the Fresnel model gives a satisfactory approximation for the diffraction of the wave on a flat optical element If we have to work with super-high resolution e-beam generators when the size of a typical structure on the element is less than the wavelengths, in principle, we need to use the Maxwell equations. Now, the calculation of direct problems of diffraction, using the Maxwell equations, are used only in cases when the element has special symmetry (for example circular symmetry). As a rule, the purpose of this calculation in this case is to define the boundary of the Fresnel model approximation. In common cases, the calculation of the diffraction using the Maxwell equation is an extremely complicated problem, even if we use a super computer. 

Several types of Eddy current probes were used with the SQUID system and the commercial system as well. High inductance wire wound probes with a ferritie eore and low induetance planar thick frhn coils were applied. The wire wound probe is the commonly used probe for high resolution conventional testing. The low inductance planar cod is more suited to be apphed in combination with the SQUID system. It is well adapted for surfaee defects and shallow defects. 

Of course, it is well known that because of the duality of the time and frequency parameters, there is no universal time-frequency technique. Indeed the two parameters cannot be simultaneously known with arbitrarily high resolution. This is expressed by the Heisenberg - Gabor inequality ... 

Sensitive parameters are necessary to compare several high resolution magnetic field sensors. Such parameters can be found with methods of signal theory for LTI-systems. The following chapter explains characteristic functions and operations of the signal analysis for linear local invariant systems and their use in non-destructive testing. 

High Resolution Computed Tomography on Large-Sized Objects. 

High-resolution computed tomography on larged-size objects... 

Marching Cubes A High Resolution 3D Surface Construction Algorithm, Computer Graphics 21(4), pp 163-169 (1987)... 

It is shown how phase contrast X-ray microtomography can be realised with a (commercial) polychromatic X-ray microfocus tomograph provided the source size and the resolution of the detector are sufficiently small and the distance between source and detector is sufficiently large. The technique opens perspectives for high resolution tomography of light objects... 

It should be noted that these results are only preliminary and have to be considered as a proof of concept. As is clear from eq. (2) the phase contrast can be improved drastically by improving the global resolution and sensitivity of the instrument. Currently, a high resolution desktop system is under construction [5] in which the resolution is much better than that of the instrument used in this work, and in which the phase contrast is expected to be stronger by one order of magnitude. 

It has been demonstrated that phase contrast microtomography is feasible with a desktop (commercial) X-ray microtomographic system The observations agree well with the theoretical predictions. This opens perspectives for high resolution microtomography of light objects. 

The first step involved massive testing at ANDREX laboratory to determine the optimal detection process. Two imaging methods were discussed, one using a linear detector array, the other using a high resolution image intensifier. 

The fish block will be moved through the X-ray beam and the resulting image is studied on the high resolution monitor. The operator has the ability to judge a block as acceptable, rejectable or downgrade able via push-button. 

In order to get an extremely high resolution and a small dead zone" (after the transmitter pulse) single amplifier states must have a bandwidth up to 90 MHz ( ), and a total bandwidth of 35 MHz (-3 dB) can be reached (HILL-SCAN 3010HF). High- and low-pass filters can be combined to band-passes and provide optimal A-scans. All parameters are controlled by software. 

Fig. 4 presents an A-scan of a 0,15 mm thick steel plate. The RF-A-.scan (sampled with 400 MHz) clearly separates the backwall echoes and demonstrates the high resolution of the HILL-SCAN 3010HF with a 50 MHz transducer. 

The internal pulser generates an output voltage of 228 V with a rise time of lower than 6 ns, which provides high resolution for frequencies above 10 MHz. The external trigger input enables synehronization with manipulators. 

BE-3S81 Past film replacement system for high resolution X>ray weld inspection with ultrasonic data fusion Mr M. Erikaen ROBITAS... 

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