Probes design

As probes must be manufactured individually for each different tube type, the probe development is an important factor for the economic use of the method. The classical procedure of probe development is a combination of experience and experiment. The new probe design is based on the experience with already manufactured probes. For an evaluation of the new design the probe must be manufactured. If the probe design is complicated, for example due to dual exciter coil arrangement or segmented differential detector coil systems, the costs of the development can be very high. Therefore a method for the pre-calculation of the probe performance is extremely useful. 

Therefore we present here a new eddy current probe designed with imaging objectives. The elements of this probe have been choosen after a relevant analysis of electromagnetic interactions. 

This new probe design associated with the preprocessings presented in this paper allows efficient flaw detection. The first tests with silicium coils probe give similar results and give great hope in future tomographic reconstruction. 

Special Inspection Problems Solved by Means of Matched Ultrasonic Probe Design. 

As examples two special probe design solutions shall be presented in this paper ... 

Up to now it was demonstrated, that the probe design enables a fast positioning and that the acoustical parameters of the probe ensure a reliable crack detection implying even a coupling control. Now, the final customer s requirement was the inspection of the blades without demounting them from the engine. 

However, this probe design is dedicated to a special turbine blade type and a special inspection task on this blade. But similar probe types and probe holders can be provided also for other engine types and for other inspection tasks like wall thickness measurement and crack detection in other zones of a blade. 

The complexity of the characterization of array probes comes from the diversity of the probe design, partly due to the piezo-composite technology which allows any shape such as Fermat surface to be achieved. We illustrate the charaeterization purpose taking three different probe examples (see figure 1) ... 

Airborne Ultrasonic Probes Design, Fabrication, Application. 

J. R. Lakowicz, ed.. Topics in Fluorescence Spectroscopy, Vols. 1—4 (Techniques-, Principles-, Biochemical Applications-, and Probe Design and Chemical Sensing), Plenum Press, New York, 1991—1994. 

The probe design includes provisions to compensate for temperature variations. This feature is not totally successful. The most reliable results are obtained in constant-temperature systems. 

Probe/Insirumentalion Developments The principles of good practice in the design, construction and location of corrosion probes have been reviewed. Specific probe designs which acknowledge hydrodynamic influences and the combined effects of mass and heat transfer have been developed. 

The significant improvements in sensitivity achieved during the last 5 years have been because of improved probe design and radiofrequency circuits. Since the probe needs to be located very close to the sample, it must be made of a material with a low magnetic susceptibility, for otherwise it would cause distortions of the static magnetic field thereby adversely affecting line shape and resolution. Much research has therefore been undertaken by NMR spectrometer manufacturers to develop materials that... 

Fig. 2.6.6 Remotely reconstructed high field NMR images of laser-polarized 129Xe gas in the hollow CAL pores. Owing to the flow pattern where the spins have to flow around two corners [see the probe design in...

Fig. 4.5.1 Photograph of the NMRI probe designed to generate a concentric cylinder shear flow. The cylinder axis is parallel to the direction of the static magnetic field B0. The front of the probe is inserted into the magnet...

A disadvantage in the utilisation of 13C NMR is the intrinsic low relative sensitivity (Table 5.14). However, higher magnetic fields and better probe design have... 

The standard RNAs were used to test the ability of the bDNA assay to quantify accurately target RNAs regardless of size or slight sequence variation. Standard RNA preparations of 1.3,2.2, and 3.2 kb showed no detectable effect on quantitation. The quantitation of standard transcripts prepared from clones of HCV sub-type la and 3a differed by a factor of 1.6-fold with one probe design and were indistinguishable with another probe design. These two 475-mer transcripts differed at 30 positions. 

The version 2.0 assay uses a different set of probes designed to hybridize to genotypes 1 to 6 with equal efficacy (Fig. 4). The new probe set not only enhanced the efficiency of binding to genotypic variants but also lowered the LOQ from 3.5 X 105 to 2 X 105 HCV RNA equivalents/ml (Detmer et al., 1996). The version 2.0 assay displayed almost a 600-fold dynamic range up to 1.2 X 108 RNA equivalents/ml. The LOQ was set at 2 X 105 to ensure a specificity of 95%. The assay was reproducible, with a mean CV of 14% for replicates of low-, middle-, and high-titer sera. Serial dilutions of quality level 1 RNA transcripts (Collins et al,... 

FIGURE 14.2 The bio-bar-code assay method, (a) Probe design and preparation, (b) PSA detection and bar-code DNA amplification and identification (reproduced from [17] with permission) (see Plate 14 for color version). 

Desirably, a probe designed for delivery of a radiopharmaceutical to cells will have the following components (Fig. 29) ... 

Apart from the primary air ratio, the ionization current depends on various other factors, such as differences in heat load, fuel gas composition, voltage supply of the probe, design of the burner, the position of the electrodes and also different temperatures of solids in the combustion chamber. All these disturbing fac-... 

B. Valeur, Principles of fluorescent probe design for ion recognition In Topics in Rwrescence Spectroscopy. Vol 4. Probe Design and Chemical Sensing (Ed. J.R. Lakowicz), Plenum, New York, 1994, pp 21-48. 

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