Radio-frequency equipment

Apart from qualification testing, a medical device should undergo a number of environmental tests, as oudined in standards such as BS 2011 (British Standard for environmental testing), CISPR 11 (limits and methods of measurement of electro-magnetic disturbance characteristics of industrial, scientific), ISM (medical radio frequency equipment), and BS4826 (British Standard for packaging electronic equipment for transport). 

Source CENELEC European Standard, CISPR 11, modified. Limits and Methods of Measurement of Radio Disturbance Characteristics of Industrial, Scientific, and Medical (ISM) Radio-Frequency Equipment, 1991. With permission. 

Curing with Microwave or Radio-Frequency Processing Equipment... 

Stray Electrical Currents and Induced Radio Frequency Currents. For information on stray currents see API 2003 [3j. For information on both hazards see the author s review Sources of Ignition in [157]. Electrostatic Discharge (ESD) Damage to Electronic Equipment. Marine Tankers and Barges (see [5] ISGOTT ). 

Radio frequency interference (RFI) EMI in electronic equipment caused by radio frequencies, ranging typically from 10 kHz (104 Hz) to 1000 MHz (109 Hz or 1 GHz). 

In these processes, specialized equipment actually deposits a fine spray of molten metal on the plastic surface. The relatively thick, rough surface is generally used in non-appearance internal surfaces for electromagnetic and radio frequency shielding, as well as static electricity dissipation. 

When fired electrically, fireworks are connected to wirebridge fuseheads. The fuseheads can inadvertently ignite if subjected to radio hazard (RAD HAZ) when in the vicinity of radio frequency sources such as cellular (mobile) telephones or walkie-talkie radios. Further advice on this should be sought from the makers of the wirebridge fuseheads and of the communication equipment because the characteristics of all these items can vary to some extent. 

RAD HAz OR RE HAz Radio Hazard. The hazard associated with the use of electro-explosive devices (EEDs) such as wirebridge fuseheads in the vicinity of radio-frequency transmitting equipment (BS 6657 Prevention of Inadvertent Initiation of Electro-explosive Devices by Radio-frequency Radiation). 

In this study, a nonchemical means of encoding the identity of each compound was used. The original polymer-bound reagent was placed in a porous microreactor equipped with a radio-frequency device that can be used for identification.168 The porous micro-... 

Electromagnetic Compatibility (EMC). In-house and site testing services are available for EMC. The Spectrum Control, Inc is equipped for testing to MIL-STD-461, MIL-I-6iSI and similar RFI (Radio Frequency Interference) specs and also performs testing in accordance with.FCC (Federal Communications Commission) and HEW (Health, Education Welfare) requirements. The personnel are familiar with RADHAZ (Radiation Hazard) filter design and measurement problems... 

The Hartshorn and Ward apparatus is a very old method for radio frequencies specified in BS 206750.This standard was declared obsolete in 1985 and no equipment is available, but it remained on the books because of reference in standards for polymeric materials. The air substitution method would be better for most purposes. 

Electromagnetic interference (EMI) refers to the interaction between electric and magnetic helds and sensitive electronic circuits and devices. EMI is predominantly a high-frequency phenomenon. The mechanism of coupling EMI to sensitive devices is different from that for power frequency disturbances and electrical transients. The mitigation of the effects of EMI requires special techniques, as will be seen later. Radio frequency interference (RFT) is the interaction between conducted or radiated radio frequency helds and sensitive data and communication equipment. It is convenient to include RFI in the category of EMI, but the two phenomena are distinct. 

Polystyrene capacitors have exceptionally low tan S values (< 10 q, making them well suited for frequency-selective circuits in telecommunications equipment. Polymer capacitors are widely used for power-factor correction in fluorescent lighting units, and in start/run circuitry for medium-type electric motors used in washing machines, tumble-dryers and copying machines for example. They are also used in filter circuits to suppress radio frequencies transmitted along main leads. Such interference noise may originate from mechanical switches, furnace controllers and switch mode power supplies it not only spoils radio and television reception but can also cause serious faults in data-processing and computer equipment. 

Recently the shielding of electronic equipment against radio-frequency and electromagnetic interference has attracted considerable interest. 

Tellurium, evaporated from a crucible, reacted with trifluoromethylthio radicals, generated from bis[trifluoromethyl] disulfane in a radio-frequency glow discharge, in a vessel equipped with a cold finger chilled with liquid nitrogen and evacuated to 0.001 torr. Trap-to-trap distillation of the material that condensed in the cold finger produced bis[trifluoromethylthio tellurium. The thermally unstable compound condensed in the - 45° trap4. 

Figure 18-5 shows a block diagram of the ENDOR apparatus. This equipment was first used in conjunction with a Varian E-12 EPR spectrometer, but is meant to show the general features of apparatus that could be used with any EPR spectrometer. The EPR cavity (Figure 18-1) was modified for the ENDOR experiment with the inclusion of a hair-pin loop around the Cryo-Tip. The loop is fed with a 50 0 transmission line from a 50-100 Watt broadband radio-frequency (rf) amplifier and is terminated with a non-inductive, water cooled 50 O resistance. 

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