ELECTRO-METRICS
8M.6992
White theaccompanying
typicalcalibrationdata
assumes
that
the indicating instrument
presents
a 50-ohmimpedance
to
theprobeandconnectingcable,thisisby nomeans
manda-
tory.
Thehighimpedance
of anRFVoltmeter
oroscilloscope
maybeusedwith theprobes.
When making before-and-aftermeasurements
to determine
the effectivenessof an attemptedEMI solution, somscaJe
should be usedto ensurethat the measurementsarerepeat-
able.Of chief importance
is thedistance
from theprobe
to
theitem undertest.Evensmallchanges
in thisspacing
can
yield largevariationsin amplitude.The E-field probes
are
alsosusceptibleto measurement
variationsdue
tocapacitive
couplingto external
objectssuchasequipment
chassis,
hu-
manbodies,largemetalobjects,etc.The H-field probes
do
notexhibit thiseffect.
Theresponse
of the
E-fieldprobes
isessentiallyomni-direc-
tional. The response
of the H-field probes
is a figure-8re-
sponse,typical of adipole.
Theprimarypickupdirection
is
broadsideto theloop,with sharp
notchesin thepickuppat-
ternin theplane
of theloop.
2.0Specifications
ModelEM-6993:
Connector:
ModelEM-6994:
Connector:
ModelEM-6995:
Connector:
6cmLoop,
H-fieldSensor.
BNC,female.
3cm
Loop,
H-fieldSensor.
BNC, female.
I cm Loop,H-field Sensor.
BNC,female.
@I/16992-2)
