Wire shielding

A special DBD configuration, called the DBGD, has been apphed in the PDRF to provide effective direct sterihzation of air flow. The DBGD consists of a thin plane of wires with equally spaced air gaps of 1.5 tmn. The high-voltage electrodes are 1-mm-diameter copper wire shielded with a quartz capillary dielectric that has an approximate wall thickness of... 

Use only inductive, DC three- or four-wire, shielded proximity sensors. Determine how close you can mount the sensor to the target. Calculate the sensor s practical sensing distance take into account the manufacturer s and temperature drift tolerances and correct for material... 

Speed 31.25 kbps voltage Cable Two wire-shielded twisted pair... 

Data Communication Wires. Electronic cables such as data communication wires employ three basic designs coaxial, twisted pair, and fiber optics (3,4) (Eig. 1). Coaxial cables are so named because the axis of curvature of its outer conductor is concentric to its inner central wire. The metal braiding wrapped around the insulated center wire acts as the return current conductor in addition to shielding the wire from various interferences. 

Eig. 1. Cable designs (a) coaxial cable (b) twisted pair cable can be unshielded, as in regular telephone wiring, or shielded (as shown here) with braiding or... 

The twists of twisted pair cable act as a shield against radio frequency interference (REI), and electromagnetic interference (EMI), and against the cross talk interference that a wire exerts on nearby wires the more twist the less interference. Telephone wires can use large numbers of pairs. In most cases the pairs are not shielded with braiding or foil, as shown in Eigure lb for data communication wire. Data communication wires work at very high... 

In industrial appHcations it is not uncommon that the thermocouple must be coupled to the readout instmment or controUer by a long length of wire, perhaps hundreds of feet. It is obvious from the differential nature of the thermocouple that, to avoid unwanted junctions, extension wine be of the same type, eg, for a J thermocouple the extension must be type J. Where the thermocouple is of a noble or exotic material, the cost of identical lead wine may be prohibitive manufacturers of extension wine may suggest compromises which are less costiy. Junctions between the thermocouple leads and the extension wine should be made in an isothermal environment. The wine and junctions must have the same electrical integrity as the thermocouple junction. Because the emf is low, enclosure in a shield or grounded conduit should be considered. 

Welding (qv) of titanium requires a protected atmosphere of iaert gas. Furthermore, parts and filler wire are cleaned with acetone (trichloroethylene is not recommended). The pieces to be welded are clamped, not tacked, unless tacks are shielded with iaert gas. A test sample should be welded. Coated electrodes are excluded and higher purity metal (lower oxygen content) is preferred as filler. Titanium caimot be fusion-welded to other metals because of formation of brittle intermetallic phases ia the weld 2oae. 

The use of carbon dioxide gas for shielded arc welding with semiautomatic microwire welding equipment has led to welding speeds up to 10 times those obtainable within conventional equipment. No cleaning or wire bmshing of the welds is required (45) (see Welding). 

Temperature Measurement shift. Measurement not representative of process. Indicator reading varies second to second. Ambient temperature change. Fast changing process temperature. Electrical power wires near thermocouple extension wires. Increase immersion length. Insulate surface. Use quick response or low thermal time constant device. Use shielded, twisted pair thermocouple extension wire, and/or install in conduit. 

Health Hazards Information - Recommended Personal Protective Equipment Rubber or plastic gloves face shield respirator fire-retardant clothing Symptoms Following Exposure Contact with eyes causes caustic irritation or burn. In contact with skin lithium react with body moisture to cause chemical burns foil, ribbon, and wire react relatively slowly General Treatment for Exposure EYES or SKIN flush with water and treat with boric acid Toxicity by Inhalation (ThresholdUmit Value) Data not available Short-Term Inhalation Limits Data not available Toxicity by Ingestion Data not available Late Toxicity Data not available Vapor (Gas) Irritant Characteristics Data not available Liquid or Solid Irritant Characteristics Data not available Odor Threshold Data not available. 

Hot wire anemometer An instrument for the measurement of fluid velocity by measuring the resistance of a fine platinum or nichrome wire, which may or may not be shielded by a silica tube. The wire resistance is proportional to the temperature and the fluid flow rate. 

Benzene (80 ml) is placed in a suitable pressure vessel (soft drink bottle or hydrogenation bottle) and chilled to 5°. The bottle is weighed, and a gas dispersion tube connected to a cylinder of butadiene is immersed in the benzene. Butadiene is introduced into the flask with continued cooling until a total of 32 g has been transferred. Pulverized maleic anhydride (50 g) is added to the bottle, which is then capped or stoppered with a stopper wired in place. The bottle is allowed to stand at room temperature for 12 hours, then is heated (behind a safety shield) to 100° for 5 hours. The bottle is cooled, then opened, and the contents are transferred to an Erlenmeyer flask. The mixture is heated to boiling, and petroleum ether is added until there is a slight turbidity. After cooling, the product is collected, mp 101-103° (yield 90%). 

Carbon Dioxide Welding metal-arc welding in which a bare wire electrode is used, the arc and molten pool being shielded with carbon dioxide gas. 

If conforming anodes or plastics shields are to be effective they must be fairly accurately located in relation to the workpiece. The practice, common in many plating shops, of wiring the work directly to the electrical bus bars over the plating tanks is, therefore, not satisfactory. Instead, the work should be mounted on rigid jigs or racks which are then suspended from the bars over the tanks. 

Thermoplastics metal wires Chemical resistance Antistatic Electrical resistance EMF shielding Flexibility Wear resistance Energy absorption Thermal stability... 

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