AC loss characteristics

ASTM D150, AC Loss Characteristics and Dielectric Constants, American Society of Testing Materials, Rhiladelphia, RA. 

ASTM D150, 1998 (2004). Test methods for AC loss characteristics and permittivity (dielectric constant) of solid electrical insulation. 

FIGURE 3.91 Test for AC loss characteristics of solid insulating materials. Power factor= W/VXI, where W= power loss in watts and VX7=effective sinusoidal voltage Xcurrent in volt-amperes. Standard test methods ASTM D150, BS 2782 method 207A. 

Standard Test Method for AC Loss Characteristics and Dielectric Constant (Permittivity) of Solid Electrical Insulating Materials, ASTM D150, Am Soc. Testing and Materials. 2004. 

AC Loss Characteristics and Permittivity (Dielectric Constant) of Solid Electrical Insulation. Primary Film Test Method ASTM D150 Additional Test Method lEC 60250. The ability of an insulator to store electrical energy can be measured through the dielectric constant, which is the ratio of the capacitance induced by two metallic plates with a film sample between them to the capacitance of the same plates with air or a vacuum between them. Better insulating materials have lower dielectric constants. Higher dielectric constants are used when high capacitance is needed. ]... 

ASTM D150 Standard Test Methods for AC Loss Characteristics and Permittivity (Dielectric Constant) of Solid Electrical Insulation includes the determination of relative permittivity, dissipation factor, loss index, power factor, phase angle, and loss angle through specimens of solid electrical insulating materials when the standards used are lumped impedances. The frequency range that can be covered extends from less than 1 Hz to several hundred megahertz. 

Insulation resistance, volume resistance, surface resistance of electrical insulating, solid materials can be determined by methods described in ASTM standard. Special standard was developed to determine permittivity (dielectric constant) and AC loss characteristics of solid electrical insulation. ... 

ASTM D150-98 Standard Test Methods for AC Loss Characteristics and Permittivity (Dielectric Constant) of Solid Electrical Insulation... 

Dielectric constant 10.15 Report results AC loss characteristics, electrical insulation (ASTM D150C) 10.15... 

Mechanical characteristics are an important consideration in the design of NbsSn conductors. The behavior during bending and under tensile stress is compared below for a tape clad on both sides with copper and a tape clad with stainless steel and copper. The NbsSn/Nb substrate ( lO mNb and 10 fim NbsSn) was prepared by liquid diffusion followed by an etching process to reduce ac losses [" ]. The copper and stainless steel cladding were bonded by soldering with an Ag-Sn eutectic. The thickness of the copper was 24 /xm for the... 

Material response is typically studied using either direct (constant) applied voltage (DC) or alternating applied voltage (AC). The AC response as a function of frequency is characteristic of a material. In the future, such electric spectra may be used as a product identification tool, much like IR spectroscopy. Factors such as current strength, duration of measurement, specimen shape, temperature, and applied pressure affect the electric responses of materials. The response may be delayed because of a number of factors including the interaction between polymer chains, the presence within the chain of specific molecular groupings, and effects related to interactions in the specific atoms themselves. A number of properties, such as relaxation time, power loss, dissipation factor, and power factor are measures of this lag. The movement of dipoles (related to the dipole polarization (P) within a polymer can be divided into two types an orientation polarization (P ) and a dislocation or induced polarization. 

The loss on ignition for the SC-155 material was 26.34 %, while the value for AC-ref was 96.80 % then the composite showed 3.67 times less carbon than the reference. Infrared spectrum of SC-155 showed exclusively the characteristic bands corresponding to silica. 

With an alternating current (AC) field, the dielectric constant is virtually independent of frequency, so long as one of the multiple polarization mechanisms usually present is active (see Section 8.8.1). When the dominating polarization mechanism ceases as the frequency of the applied field increases, there is an abmpt drop in the dielectric constant of the material before another mechanism begins to dominate. This gives rise to a characteristic stepwise appearance in the dielectric constant versus frequency curve. For each of the different polarization mechanisms, some minimum dipole reorientation time is required for reahgnment as the AC held reverses polarity. The reciprocal of this time is referred to as the relaxation frequency. If this frequency is exceeded, that mechanism wUl not contribute to the dielectric constant. This absorption of electrical energy by materials subjected to an AC electric held is called dielectric loss. 

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