Hitachi S-4800 manual Power Line Noise and Electric Field Noise, External Noise Sources

1.1.8Power Line Noise and Electric Field Noise

Image troubles may be observed when a device as given in Table 1-3 or its power line is installed nearby or, even if it is distant, it is a heavy duty type. When selecting the installation site, therefore, whether a source of interference is located nearby or not must be checked.

In case an equipment energized by power of a frequency different from the commercial frequency employed on the Model S-4800 or the power line for it is located nearby, scan synchronization with power line frequency will become ineffective. Such a location should be avoided.

Table 1-3 External Noise Sources

Classification		Noise	Source Equipment
		Source
Small-sized	Electric equipment	Electric discharge	Flasher (neon sign, ornamental electric bulb),
electric	with contacts	(spark, arc)	relay, electromagnetic contactor, thermostat
equipments			(warmer, refrigerator, heating iron), cash
			register
	Equipment utilizing	Electric discharge	Electric drill, laboratory engine, motor of
	commutator motor	(spark, arc),	sewing machine, cleaner, food mixer, shaver,
		sliding contact	massaging machine
	Electric discharge	Glow discharge	Neon discharge tube, high pressure mercury
	tube		arc lamp
	Controller utilizing	Phase control	Thyristor dimmer, inverter
	semiconductor	(transient noise)
Equipment using	Industrial high	Electro-magnetic	Industrial high frequency heater, high
high frequency	frequency equipment	emission	frequency electric welder, microwave oven
	Medical high	Electro-magnetic	VHF/UHF fulgurators, electric scalpel
	frequency equipment	emission
	Equipment utilizing	Electro-magnetic	Flaw detector, depth sounder, fish finder,
	ultrasonic wave	emission	ultrasonic cleaner
Power equipment	Power cable	Electric or magnetic	Induction of commercial frequency
	(transmission line)	filed,	(electrostatic induction, electromagnetic
		Ground current	induction, current leaking in ground)
		Electric discharge	Corona, poor insulator, poor contact due to
		(corona, arc)	corroded metal (arc discharge)
	Electric railroad / train	Electric discharge	Trolley wire, internal equipment, rectifier
		(spark, arc)
		Magnetic field	Current flow deviation
Internal	Automobile	Electric discharge	Ignition system
combustion
		Other	Dynamo, voltage regulator, wiper, horn,
engine
			winker
Large power		Electro-magnetic	Broadcasting equipment, radar
radio frequency		emission
equipment
		Electro-magnetic	Radio transceiver
		emission
.

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