Protector devices

Current-responsive protector Devices that inclnde time-lag fuses, magnetic relays, and thermal relays (normally located in the motor or between the motor and controller) that provide a degree of protection to the motor, motor control apparatns, and branch-circuit conductors from overloads or failures to start. 

Are cylinders with water weight capacity over 30 pounds (13.5 kg), equipped with means for connecting a valve protector device, or with a coUar or recess to protect the valve ... 

The deposition temperature range is 300-500°C, the partial pressure of the alkyl is 0.5-2.5 Torr, and that of THF is 20-80 Torr. ZnO has found applications in piezoelectric devices, transducers, coatings for photoconductive devices, and non-linear resistors (varistors), and overvoltage protectors. 

The elimination of this rapid energetic surge requires special devices and can not be prevented by crowbars, gas diodes, or overvoltage protectors commonly found in computers and power supplies. Considerable problems exist with filtering devices, unless they are especially made with much higher than expected insulation requirements and are used in conjunction with fast, specifically designed overvoltage protectors. 

Another common reason to add a filler to a polymer is to increase either electrical conductivity or thermal conductivity. Polymers typically have electrical conductivity from 10 to 10 S/cm though the addition of a moderately conductive filler such as carbon black conductivities of lO -lO S/cm are possible highly conductive fillers such as silver can raise this value to 10 -10 S/cm. Applications include static dissipative devices and surge protectors. The impact of adding a highly thermally conductive filler to a polymer is much smaller at low-volume fractions vs. the impact of an electrically conductive filler on electrical conductivity. However, if a highly loaded stiff product is acceptable, polymer composites are capable of dissipating substantial amounts of heat. 

GAGE PROTECTOR A device used to transfer grout pressure to a gage without the grout coming in actual contact with the gage. 

For children up to 4 years of age an infant protector has been developed for OCDM by the Army Chemical Corps (Figure 2). This pup tent-like device... 

During the war, the CWS also initiated a major civil defense program to protect civilians against both chemical and biological weapons. Of particular concern were protective devices for children. With the help of Walt Disney, a Mickey Mouse gas mask was designed for children, in the hope that they would not be frightened if they had to wear it, and a tentlike protector was designed for in-fants.26,30,102 104... 

Electronic devices/systems assembly fiberoptic connectors, 395, 396 luminaire wiring, 394-395 measuring instruments, 392-394 overload protector, 392 Electronic auctions, 271 Electronic boardroom, 134 Electronic commerce (e-commerce), 259-278 and advertising, 272, 273 and associations/referrals, 273... 

A varistor is used in an electric circuit as protection against large voltage pulses, i.e., a surge protector. Such devices are particularly important in protecting microelectronic devices. ZnO is the most widely used and important material for varistors. 

The SIL3 Hoist Protector will be scalable, in terms of, providing supervision and control functionality for different types of Mine Hoist and type of transport (personnel and material), Inputs/Outputs channels and used field devices. 

Lenses are tested to withstand the impact of a 2.5-cm (1-inch) ball dropped from 127 cm (50 inches), plus a penetration test for plastic lenses as required by American National Standards Institute (ANSI) Z87 for all eye and face protectors, two-level classification for impact protection. See ANSI Z87.1-2003, Standard for Occupational and Educational Eye and Face Protection Devices. 

Devices used to protect the head from injury. These include safety helmets or hard hats that are primarily used to protect the head from falling objects or overhead hazards industrial scalp protectors such as bump caps that protect against striking fixed objects, scalping, or entanglement and caps and hair nets, which are used to prevent the hair from coming in contact with moving machinery or the parts of machinery. 

S3.19-1974, American National Standard for the Measurement of Real-Ear Hearing Protector Attenuation and Physical Attenuation of Earmuffs. When estimating A-weighted noise exposures, it is important to remember to first subtract 7 dB from the NRR and then subtract the remainder from the A-weighted noise level. The NRR theoretically provides an estimate of the protection that should be met or exceeded by 98 percent of the wearers of a given device. In practice, this does not prove to be the case, so a variety of methods for de-rating the NRR have been discussed. Non-auditory Effects of Noise... 

Devices worn by the worker to protect against hazards in the environment. For example, respirators, gloves, and hearing protectors. The use of personal protective equipment is the least preferred method of protection from hazardous exposures. It can be unreliable and, if it fails, the person can be left completely unprotected. This is why engineering controls are preferred. Sometimes, personal protective equipment... 

List the dBA levels of various equipment and tasks. For example, rock drilling can reach 115 dBA, chain saws 125 dBA, abrasive blasting 112 dBA, heavy equipment 110 dBA, demolition 117 dBA, and needle guns 112 dBA. Show slides of the equipment/tasks that require hearing protectors. Dispell myths about workers getting used to the noise. Have samples of all approved hearing protective devices. Indicate where workers can find hearing protectors. 

Hearing protection — If exposure limits are exceeded even after engineering and administrative controls are implemented, your company will provide you with proper hearing protection. If you will be using insert hearing protectors, they must be fitted by a competent person. A competent person is someone who can tell the difference between a good fit and a poor fit. Plain cotton is not an acceptable protective device. 

Extension devices equipped with surge protectors can be permanently used with equipment that contains microprocessors, such as computers, but surge protectors should not be used in areas subject to moisture, physical or chemical damage, or flammable vapors. 

The largest voliune of polsrmeric materials used in dentistry is in prosthetic applications. Polymeric materials are also important in operative dentistry, being used to produce composite resins, dental cements, adhesives, cavity liners, and as a protective sealant for pits and fissures. Elastomers are employed as impression materials. Resilient prosthetic devices are oft en fabricated to restore external soft-tissue defects. Mouth protectors are fabricated to prevent injury to teeth, as well as prevent head and neck injinaes. Other polymer applications include fabricating patterns for metal castings and partial denture frameworks, impression trays, orthodontic and periodontal devices, space maintainers, bite plates, cleft palate obdurators, and oral implants. Polymeric materials may also be used to fabricate an artificial tongue, when disease results in its loss. 

Protective devices—(i) Circuits exposed to power conductors. Communication circuits so located as to be exposed to accidental contact with light or power conductors operating at over 300 volts shall have each circuit so exposed provided with an approved protector. 

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