Wiring methods

EXPLOSION-PROOF LIGHTING FIXTURE INCANDESCENT AND MERCURY VAPOR (FOR EXTERNAL BALLAST) 

Divisions 1 and 2, Group D areas. (Courtesy of Crouse-Hinds Electrical Construction Materials, a division of Cooper Industries, Inc.) 

In Division 1 areas, the National Electrical Code (NEC) allows only the following wiring methods  

Tlireaded rigid metal conduit must be threaded with an NPT standard conduit cutting die that provides %-in. taper per foot, must be made up 

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Chapter III. 1 Heptene (111,10) alkyl iodides (KI H3PO4 method) (111,38) alkyl fluorides (KF-ethylene glycol method) (111,41) keten (nichrome wire method) (111,90) ion exchange resin catalyst method for esters (111,102) acetamide (urea method) (111,107) ethyl a bromopropionate (111,126) acetoacetatic ester condensation using sodium triphenylmethide (111,151). 

In Division 2 areas, the NEC allows the wiring methods that follow ... 

Exposure of coupons or specimens to the process stream cannot be achieved satisfactorily unless they are rigidly supported in a rack, although in some cases it may be possible to simply hang them in by means of a wire. Methods of exposure coupons are described in ASTM Method G4 1984. 

The hot-wire method is a transient method and can yield an absolute value. A long, thin wire, through which electric current is passed stepwise, is placed in a melt, when... 

A number of variations of the transient hot-wire method have been devised, and an optical method to detect the temperature rise has been used. A modified transient hot-wire technique using a mercury-incapillary probe was introduced by Nagashima et al., in which a thin mercury thread was used as a heater-thermometer and the capillary wall as an insulator. Using this method, they measured the thermal conductivity in mixture systems such as (Na, K)N03, (Li, Na)N03, and HTS(KN03-NaN03-NaN02, 44-7-49 mol.%). ... 

The data on molten NaNO, are summarized in Table 16. Nagasaka and Nagashima reeommended the following empirieal relation obtained by the transient hot-wire method with eeramic-coated probes ... 

A square end is more easily obtained by the hot wire method. The tubing is first scratched all the way round. This may be done by... 

In an attempt to understand the combustion mechanism of catalyzed double-base propellants, several investigators have conducted experiments to measure the burning rates of strands of liquid nitrate esters. The various measurement techniques were very similar to that employed in a conventional solid propellant strand burner. The liquid esters were placed in a tubular container, and the liquid surface regression speeds were measured by optical methods or by the fuse-wire method used in solid-propeUant strand burners. The only important difference between the solid and the liquid strand burning-rate measurements is that the liquid strand burning speed is very much dependent on the diameter of the container. 

The exploding wire method involves putting a large amount of energy into a wire suddenly, causing it to explode. If 02 is present, a metal oxide aerosol is produced, whereas particles of pure metal are formed in an inert atmosphere such as helium. Exploding wire generators and their size distribution characteristics have been discussed by Phalen (1972). 

Since die wire method of control restricted the maneuverability of launching planes and required that they remain in the vicinity of missiles, thus exposing themselves to the weapons of enemy s bombers, the wire control method was replaced in the latter model of the X-4 by an acoustic homing device Kranich. With the latter device the parent plane could execute an evasive maneuver the moment the missile was launched and then withdraw itself beyond die range of enemy bombers weapons (Ref 3, p 216)... 

The criterion used at TCC-RMD to detect the detonation is to measure the velocity of the detonation wave. The constant current resistance wire method, originally developed at the U.S. Naval Ordnance Laboratory (7), is the technique used. This method depends on the high degree of ionization existing in the reaction zone of a detonation. The advancing detonation front completes the circuit between a central resistance wire and another conductor, which may be the metal test container or a separate wire, maintained at ground potential. The method provides a permanent record of a complete and accurate history of a detonation as it passes through a container of any size or shape. Needless... 

Sedoi, V.S., Ivanov, Y.F., and Osmonolie, M.N. (2003) Study of ultra fine powders produced by the exploding wire method. Proc. 34th Ind. Ann. Conf. of ICT,... 

Sedoi, V.S., and Valevish, V.V. (1999) Direct production of nano sized powders by the exploding wire method, in Physics, Chemistry and Applications of Nano Structures (Nanomeeting-99) (eds. V.E. Borisenko, A.B. Filonov, S.V. Gaponenko and V.S. Gurin.), World Scientific Publishing Company, New Jersey, USA, p. 322. 

Hori, T. 1985. Objective measurement of the process of curd formation during rennet treatment of milks by the hot wire method. J. Food Sci. 50, 911-917. 

A common transient method is the line source technique, and such an apparatus was developed by Lobo and Cohen41 which could be used with melts. Oehmke and Wiegmann42 used the line source technique for measurements as a function of temperature and pressure. A hot wire parallel technique43 yielded conductivity and specific heat from the same transient, and then diffusivity was calculated. Zhang and Fujii44 obtained conductivity, diffusivity and the product of density and specific heat from a short hot wire method. 

A comparison of guarded hot plate, transient plane source and modified hot wire methods has been made54 using polyurethane foam, and the strengths and weaknesses of the techniques discussed,... 

Elimination of coupling medium by shielding, use of proper wiring methods, and conductor routing... 

W. R. Davis, Hot-Wire Method for the Measurement of the Thermal Conductivity of Refractory Materials , in Compendium of Thermophysical Property Measurement Methods, (K. D Maglic, A. Cezairliyan, and V. E. Pelet-sky, eds.), Vol. 1, Plenum Press, NY (1984). 

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