Radio interference

Additional test on an IPB enclosure for radio interference as in NEMA-107. The maximum radio influence voltage (RIV) should not exceed 100 //V at 1000 kHz. For test equipment and test procedure refer to the Standard. 

Effect of plant on surroundings, drainage, pollution, transport, wind and light change, source of ignition/vibration/noise/radio interference/fire spread/explosion Effect of surroundings on plant (as above)... 

Commercially available carbon resistors have been used as temperature sensors in the cryogenic temperature area near absolute zero, from about -253°C to -272°C (-424°F downward to below -458°F). One major benefit of the carbon resistor at low temperature is its lower susceptibility to adverse effects caused by a magnetic field and stray radio interference. They do require individual calibration to keep the measurement error under 1%. Carbon resistors may be incorporated into resistor networks to improve linearity. These sensors exhibit a large increase in resistance below -253°C ( 424°F). Reproducibility on the order of 0.2% is obtainable when calibrated individually. Small size, low cost, and general availability make their use attractive in cryogenic work. 

CISPR International Special Committee on Radio Interference (part of lEC)... 

EN55014 Specification for radio interference limits and measures for equipment embodying small motors, contacts, control and other devices causing similar interference. 

EN55015 Limits and methods of measurement of radio interference characteristics of fluorescent lamps and luminaires. 

VDE0875 Specification for radio interference suppression of electrical appliances and systems. 

The stepped-FM UWB sensor can detect radio interference by monitoring the phase detector output in passive mode (transmitter power off/receiver on) and is then designed to have some spectrum hole (nonactivated within a portion of the wide radio spectrum) at the transmitter in order to prevent any conflict and to coexist with the other narrow-band wireless systems. Note that the transmit radio consists of independent narrow-band pulses with a different frequency. As such, if provides the flexibility to support... 

Experience from operation indicates that the interference can be initiated by both on-site (high voltage switch gears, portable telephones, portable electronic devices and computers) and off-site (radio interference and telephone network) sources. 

An accumulation of devices of this kind will therefore always be problematic. It shall be mentioned at this point that for the application of chopped devices special measures for radio interference suppression must be taken. 

When the main arc has been struck in the low-pressure mercury vapour, the current is limited by the choke. The capacitor across the mains supply provides power-factor correction and the capacitor across the starter switch contact is for radio interference suppression. 

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