Glasses volume resistivity

Electrical Conductivity of Metals Electrical Resistivity of Metals Electrical Resistivity of Alloy Cast Irons Resistivity of Ceramics Volume Resistivity of Glass Volume Resistivity of Polymers... 

Types of Glass Volume Resistivity, ohm-cm Dielectric Constant, 1 Mhz Dissipation Factor, 1 Mhz... 

FIG. 121. Volume resistivity of some commercial glasses (from Kingery, i960) ... 

Properties Clear, very viscous, pale-yellow liquid. D 1.20 (20/20C), fp (sets to a glass at -10C), bp >300C, flash p >375F (190C), refr index 1.615 (25C). Combustible. Viscosity decreases very rapidly when heated has high volume resistivity, low power factor, unusually high dielectric constant. 

For the physical-chemical analysis volumes between lOOmL and 3L are collected using manual or automatic devices. The water samples are collected in colorless glasses, chemically resistant (pyrex glass with fixed composition) but lately, because of their fragility polyethylene vessels with the following advantages replaced these ... 

The measurement of bulk resistivity of a powder includes volume and surface conduction mechanisms. It is generally not possible to separate out the two effects so that the effective powder resistivity, either the volume or surface resistivity, for dielectric and insulating particles such as glass depends on such factors as the presence of surface impurities and the relative humidity. For clean metal powders, the volume resistivity will dominate conduction in a bed of particles whereas, the presence of a surface oxide film can dominate conduction via the contact resistance for only lightly compacted powders. 

In contrast to surface resistivity, the volume resistivity of glass and ceramics is controlled largely by its composition. For example, the conductivity of sodium silicate glass increases in direct proportion to the sodium ion concentration (Kingery et. al., 1976). Electronic conduction is also possible in... 

The volume resistivity/temperature curve clearly illustrates the strong difference in the temperature dependency of the volume resistivity of a polymer in its glassy phase and in its rubbery phase. The Tg-value, obtained by drawing two tangents near this glass-rubber transition, is determined at 1000/T 3.58 or 6°C. This Tg-value is a real static Tg-value and its hypothetical frequency [f(h)l in the frequency/temperature plane will be lower than the f(h) = lxB-2 to lxE-4 claimed by Phillips [12] for dilatometric experiments. A good fit on the Arrhenius plot was obtained assuming an f(h) of lxE-6 for this Tg-value, see below. 

The DC properties of anti-static epoxy GFR pipes The use of glass-fibre reinforced (GFR) epoxy resin pipes is, especially in tankers, hampered by the bad electrostatic properties of these pipes. The possibility to decrease the volume resistivity to an acceptable level using only a small amount of carbon black (see 5.3.2) resulted in the development of the WAVIMAR anti-static GFR pipe system by Wavin BV. This pipe system is based on a liquid DGEBA/MDA (100/27) and cured for two hours at 120°C, containing about 1.5 %wt. (on the resin phase) of Ketjen black EC-2000 carbon black. The specific volume resistivity of a sample of such a pipe was measured as a function of the direction, the field strength and the pipe wall thickness. 

At ordinary temperatures, PVC compounds are reasonably good electrical insulators over a wide range of frequencies, but above the glass transition temperature their value as an insulator is limited to low-frequency applications. The volume resistivity decreases as the amount of plasticizer increases. 

Plastic Glass-fiber content, wt% Heat deflection temp at 1.7 MPa°, °C D 648 Coefficient of linear thermal expansion, 10 cm/cm/°C, D696 Maximum temp, continuous use, C Water absorption, 24 h, %, D570 Volume resistivity, cm, D257 Dielectric strength dry, V/pm, D 149 Mold shrinkage, cm/cm,D955... 

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