Specific absorption volume resistivity

Resin material Power factor, 60 cycles Arc resistance, sec Water absorption %-24 hr Rockwell hardness Specific gravity Mold shrinkage, in./in. Volume resistivity, ohra/cm Dielectric constant, 60 cycles Dielectric strength, STI/8VPJd. 

Ffg. 24. Dependence of dielectric perme ability e (1), tangent of dielectric loss angle (2), specific volume resistance (3) and water absorption (4) on the curvii period for epoxide foams (7 = 35 kg m ) at 98% relative humidity... 

Specific gravity Tensile modulus Flexural modulus Tensile strength Flexural strength Impact strength Thermal expansion Heat deflection temperature Dielectric constant Volume resistivity Water absorption... 

Some of the properties documented in the specification sheets of IPC-4101 include Tg, copper peel strengths at different conditions, volume resistivity, surface resistivity, moisture absorption, dielectric breakdown voltage, permittivity, loss tangent, flexural strengths and arc resistance. These properties will be discussed further in Chap. 8. 

VOLUME resistivity The electrical resistance between opposite faces of a 1-cm cube of insulating materials, commonly expressed in ohm-centimeters. The recommended test is ASTMD 256 51T. Also called the specific insulation. vulcanization A chemical reaction in which the physical properties of an elastomer are changed by causing the elastomer to react with sulfur or some other cross-linking agent. WATER absorption The ratio of the weight of water absorbed by a material to the weight of the dry material. 

ASTM C 522 covers the measurement of airflow resistance and the related measurements of specific airflow resistance and airflow resistivity of porous materials that can be used for the absorption and attenuation of sound. The method describes how to measure a steady flow of air through a test specimen, how to measure the air-pressure difference across the specimen, and how to measure the volume velocity of airflow through the specimen. The airflow resistance, R, the specific airflow resistance, r, and the airflow resistivity, rQ, may be calculated from the measurements. The apparatus includes a suction generator or positive air supply arranged to draw or force air at a uniform rate through the specimen. A flowmeter is used to measure the volume velocity of airflow through the specimen, and a differential-pressure-measuring device measures the static-pressure difference between the two faces of the specimen with respect to atmosphere. 

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