Sheet resistivity definition

Resistor Noise. The random motion of current carriers causes spontaneous fluctuations in electric current, termed electrical noise. Current noise in thick-film resistors is called excess noise, as it is considered the excess noise over thermal noise. Thermal noise is predictable and is a function of resistance and temperature, whereas current noise has no definite relationship. Noise in thick-film resistors depends on the sheet resistance value, thickness of the resistor print, and geometry of the resistor. Figure 8.59 shows a typical plot of measured noise versus resistor area for a 200-kQ/sq resistor. Current noise decreases as resistor area increases. Resistor noise also depends on processing conditions. Generally, noise decreases with an increase in peak firing temperature. The typical noise value for commercial thick-film resistors is shown in Table 8.20. 

Incorporation of 0.1—4% zeolites 13X, 5A, 4A, lOX, XW and ala) natural zeolites and synthetic pdyn rs (polystyrene, vinyl chloride-vinyl acetate copolymer, poly propylene, acrylonitrile, butadiene styrene copolymer, poly (methyl methacrylate or polyetl lene) containing 0.1-4% antistatic agent improves antistatic properties. However tire zeolites alone fail to do so In another instance a composition of polyvinylchloride 100, dioctylthalate 80, stabilizer 2, Pd-stearate-1, and zeolite 100 parts is rolled at 160 ° and pressed to give a white sheet having surface resistivity 3.8 x 10 ohm-cm coitq>ared with 1.5 X 10 ohm-cm for a similar sheet containing calcium carbonate in place of zedite, vdiich reflects the definite role of these zeolites in improving the antistatic properties of the composition. 

Acryiic Resin AS. See Acrylic resin Acrylic resin. See Polyacrylic acid Acrylic sheet. See Acrylic resin Acrylic/styrene/acrylonitrile terpolymer Synonyms Acrylonitrile/styrene/acrylate Acrylonitrile-styrene-acrylic ester copolymer ASA ASA terpolymer Definition Thermoplastic blend produced by polymerization of acrylonitrile and styrene in presence of acrylic ester latex Properties Dens. 1.08 kg/l (20 C) tens. str. 50-60 MPa tens. mod. 2500 MPa better heat and It. resist, than ABS... 

Definition Ceramic material containing silica (sand) (75%), soda ash (20%), and lime (5%), often combined with metallic oxides the blend Is heated to fusion temps., then annealed to a rigid, friable state Properties Plate, sheet, fiber, flakes, filament, fabric, rods, tubing, pipe, powd., beads, flakes, or hollow spheres sp.gr. 2.5 hardness (Mohs) 5.5 high str., dimensional stability, heat and chem. resist. 

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