User manual

EMF450-en-GB_V1.1 8/15

Definitions

 ElectromagneticRadiation

Thismeterisusedtoindicateradiatedelectromagneticfieldswhereverthereisavoltage,

current,electric(E)ormagnetic(H)field.Examplesincludetheelectromagneticfieldsfrom

radiobroadcasting,TVtransmittersandpowerlines.

 ElectricField Strength

Thisisafieldvectorquantitythatrepresentstheforce

(F)onaninfinitesimalunitpositive

testcharge(q)atapointdividedbythatcharge.Electricfieldstrengthisexpressedinunits

ofvoltspermeter(V/m).Usetheunitsofelectricfieldstrengthformeasurementsinnear‐

fieldpowermeasurements.

 Magneticfieldstrength (H)

Thisisafieldvectorthatisequaltothemagneticfluxdensitydividedbythepermeabilityof

themedium.Magneticfieldstrengthisexpressedinunitsofamperespermeter(A/m).

Thismeasurementisfornear‐fieldpowermeasurements.

 Powerdensity(S)

Powerperunitareainthedirectionofpropagation;usually

expressedinunitsofwattsper

squaremeter(W/m2)or,forconvenience,milli‐wattspersquarecentimeter(mW/cm

).

 Thecharacteristicofelectromagneticfields

Electromagneticfieldspropagateaswavesandtravelatthespeedoflight(c).

Thewavelengthisproportionaltothefrequency.

λ(wavelength)=

c (speed of light)

f (frequency)



Near‐fieldisassumedifthedistancetothefieldsourceislessthanthreewavelengths.For

far‐fields,thedistanceismorethanthreewavelengths.Inthenear‐field,theratioof

electricfieldstrength(E)andmagneticfieldstrength(H)isnotconstant,someasureeach

separately.Inthe

far‐field,however,itisenoughtomeasureonefieldquantity,and

computetheotheraccordingly.



Descriptions

FrontPanelDescription

1. 2.4”ColorTFTdisplay(240*320resolution)

2. SelectandDownbutton

3. PowerandMenubutton

4. MiniUSBinterfacejack

5. HoldandEnterbutton

6. Batterycompartmentcoverand

measurementchartonbackofmeter

Figure1–MeterDescription