Basic Electrical Testing Methods

In the electrical field the International Electrotechnical Commission (IEC) performs the same function as ISO. The work of this body is of interest where rubbers are used in electrical insulation, etc. As regards electrical test methods for rubber, ISO and BSI have tended to adapt the basic procedures and principles standardised by IEC or to rely on the IEC standards. 

A noncontact electrical test system can detect all open/short failures for 50- nn-pitch fine traces without pin contacts. It does not make any dents or cause damage on the fine traces. It works for fragile, fine flying leads because it is a non-contact inspection system. The basic principle of the method is illustrated in Fig. 67.1. 

Property data for GRTP s are presented in two major breakouts. In the first breakout, the basic resins—styrene acrylonitrile (SAN), polycarbonate, polysulfone, polyacetal, polypropylene, polyphenylene oxide (PPG), nylon, modified PPG, and polyvinyl chloride—are treated as the independent variables and the physical, mechanical, electrical, thermal, chemical, and weathering characteristics are treated as the dependent variables. In the second breakout, the functional relationships are reversed, te., the properties are the independent variable and the resins are the dependent variable. ASTM test methods by which the physical values were determined are listed. The. physical data versus resins are presented in both tabular and graphic form. 

Eddy-Current Methods This is one of the earliest NDT methods and is still used Basically, this method reveals any differences tn electrical impedance between parts to be tested and a reference sample. Parts to be examined are passed through a coil or explored with a probe, and a trace appears on a CRT, Since magnetic and electrical characteristics are closely related to metallurgical quantities, a trace position or pattern or a meter reading clearly shows variations in metal hardness and composition, as well as defects. Both ferrous and nonferrous parts can be tested, and various coils, probes, and detector lips are available,... 

The direct transformation from the output pattern to the taste quality was performed here as one trial of expressing the actual human sensation using the output electrical pattern. A similar trial was done for evaluation of the strengths of sourness and saltiness, which will be mentioned later. These two trials depend on the utilization of simple transformation equations by extracting typical properties of output patterns. This method is effective if some data on sensory tests, using humans as a standard, can be obtained to compare with the sensor outputs. However, the expressions for the tastes of beer are obscure because they are not described by the five basic taste qualities. The purpose of the application of the taste sensor is also to express these kinds of obscure terms of human sense in scientific terms. 

An overview of relativistic state-of-the-art calculations on electric field gradients (EFG) in atoms and molecules neccessary for the determination of nuclear quadrupole moments (NQM) is presented. Especially for heavy elements four-component calculations are the method of choice due to the strong weighting of the core region by the EFG operator and the concomitant importance of relativity. Accurate nuclear data are required for testing and verification of the various nuclear models in theoretical nuclear physics and this field represents an illustrative example of how electronic structure theory and theoretical physics can fruitfully interplay. Basic atomic and molecular experimental techniques for the determination of the magnetic and electric hyperfine constants A and B axe briefly discussed in order to provide the reader with some background information in this field. 

ABSTRACT We are working on non-destructive evaluation of metal quality by the electric conductivity. We use contactless method with eddy currents to probe the metal piece. Here we are testing and verifying the theoretical methods for later use in practical algorithms in fast metal conductivity evaluation. In this particular work we compare the basic eddy current theory of coil impedance with the same scenario modeled with Finite Element Method (FEM). We foimd very good correlation between the theory and Finite Element Method below 2 kHz. 

The goal of cabbration methods is to provide the DUT with an electrically pure connection to the test system terminals. This means that the signal at the test ports should have zero magnitude, no phase shift, and a characteristic impedance of Zg. Mathematically, it means to place an error model between the test setup and the DUT, so that it can account for any errors due to the testing device. Calibration is a procedme that basically quantifies these errors [33-36]. 

Spot test analysis makes frequent use of electrochemical separation methods. Especially in paper chromatography use is made of differential diffusion in which an electrical field serves to accomplish the desired separation. Of particular interest in spot test analysis is the employment of electrographic methods for examining metals, alloys and ores. The basic principle employed is the anodic solution of the metals. In practice, the specimen is made the anode and a piece of aluminum foil serves as cathode. Filter paper is moistened with the appropriate reagent solution and then placed between these two electrodes. The proper voltage is then applied. The movement of the metals then leads to an imprint on the paper and so reveals the exact position of the metals that have migrated from the surface of the test specimen. Hermance and Wadlow have published a comprehensive review of this procedure. 

Three basic tests have been developed and accepted by the plastics industry. If the application does not require the product to be exposed to elevated temperature for a long period under continuous load, a simple heat-resistance test is adequate. The applications requiring the product to be under continuous significant load must be looked at from creep modulus and creep rupture strength test data. Another widely accepted method of measuring maximum continuous use temperature has been developed by Underwriters Laboratories. The UL temperature index, established for a variety of plastic materials to be used in electrical applications, is the... 

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