3M CTM051 User Manual page 11

EMI Measurements
High frequency noise (EMI) on a ground causes equipment malfunction and
damage to sensitive components. The 3M
Meter measures
high-frequency noise
on a ground in a
wide frequency and
dynamic range.
High-frequency
noise is measured
in two different
units — volts and
dBuV. The latter is a
logarithmic measure
of voltage where 0dB
is referenced to 1uV.
In order to measure
EMI on a ground, press the EMI button. The screen will show the average
value of the high-frequency signal in Volts on the top display line and the
magnitude of the envelope peak of the signal (i.e. transients or spikes) on
the bottom line. By pressing the EMI button one more time you can switch
to dBuV units, as shown above.
Autoscale
The Ground Pro uses autoscaling in EMI mode — no scale switching is
necessary.
Ground Pro Ground Integrity
™
EMI
AVG
0 2 4
AVG
0 2 4
PEAK
V
Peak EMI in V
Average EMI in V
V
Relative peak value
PEAK
dB
µ V
Peak EMI in dBuV
Average EMI in dBuV
dB
µ V
Relative peak value
10