Hitachi Microscope & Magnifier S-3400N User Manual

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1.2  Installation Requirements 
1 - 12 
Table 1.2-3    External Noise Sources 
 
Classification 
Noise 
Source 
Source Equipment 
Electric equipment 
with contacts 
Electric discharge 
(spark, arc) 
Flasher (neon sign, ornamental electric 
bulb), relay, electromagnetic contactor, 
thermostat (warmer, refrigerator, heating 
iron), cash register 
Equipment utilizing 
brush type motor 
Electric discharge 
(spark, arc),   
sliding contact 
Electric drill, laboratory engine, motor of 
sewing machine, cleaner, food mixer, 
shaver, massaging machine 
Electric discharge 
tube 
Glow discharge 
Neon discharge tube, high pressure 
mercury arc lamp 
Small-sized 
electric 
equipments  
Controller utilizing 
semiconductor 
Phase control 
(transient noise) 
Thyristor dimmer, inverter 
Industrial high 
frequency 
equipment 
* Electro-magnetic 
emission 
Industrial high frequency heater, high 
frequency electric welder, microwave 
oven 
Medical high 
frequency 
equipment 
* Electro-magnetic 
emission 
VHF/UHF devices, electric scalpel 
Equipment 
using high 
frequency 
Equipment utilizing 
ultrasonic wave 
* Electro-magnetic 
emission 
Flaw detector, depth sounder, fish finder, 
ultrasonic cleaner 
Electric or 
magnetic filed, 
Ground current   
Induction of commercial frequency 
(electrostatic induction, electromagnetic 
induction, current leaking in ground) 
Power cable 
(transmission line) 
Electric discharge 
(corona, arc) 
Corona, poor insulator, poor contact due 
to corroded metal (arc discharge) 
Electric discharge 
(spark, arc) 
Trolley wire, internal equipment, rectifier 
Power 
equipment 
Electric 
railroad/train 
Magnetic field 
Current flow deviation 
Electric discharge
Ignition system 
Internal 
combustion 
engine 
Automobile 
Other 
Dynamo, voltage regulator, wiper, horn, 
winker 
*Electro-magnetic 
emission 
Broadcasting equipment, radar 
Large power   
Radio frequency 
equipment 
 
Electro-magnetic 
emission 
Radio transceiver 
 
*  Emission that are signals in a given system but cause interference in other systems.