Re: Measurement Uncertainty

[WOODS, RICHARD]

ETSI limits assume a maximum level of uncertainty. For example,  I-ETS
300330, Short Range Devices 9kHz-25MHz, specifies that the uncertainty
for radiated emissions is to be no more than 2 dB with a 95% confidence
level when using the antenna substitution method. If the antenna
substitution method is not used, the uncertainty factor rises to 6 dB.
Using the latter method means that the measured emission level must be 4
dB below the limit due to the increased uncertainty.  The uncertainty of
the conducted emissions is to be no more than 3 dB.