NARDA 8718B, User Manual

Page: 62 / 137

61 Chapter 9 Time-Averaged Measurements
The PAUSE feature
can be useful when
measuring the aver-
age value from cer-
tain rotating radars.
The effective mea-
surement technique
requires you to
pause during the pe-
riod of time when you
are not in the beam
of the
radar. Continue this
technique for two or
more revolutions (de-
pending on the RPM)
to ob-
tain a
realistic
average
value of the field in
the beam at your lo-
cation. For details on
this measurement
technique, see Radar
Measurements in the
Applications Booklet.
N
ote
2. You may continue to pause and start the averaging as
many times as needed. The time interval initially
selected applies only to the measurement time.
3. To end time averaging while * PAUSED* , press
F4 ( STOP ).
To change the averaging interval...
1. To change the averaging interval (once the current
measurement interval has been completed or
stopped), press F4 ( QUIT ). To initiate a new time
averaging interval, use the menu system to select
TIME AVG from the First Menu Screen .
2. Proceed as previously described to select FIXED
TIME from the averaging menu screen and then the
new averaging interval.
Mode 2 Averaging
Mode 2 averaging (time averaging to meet the requirements of
a specific standard) requires two parameters to be properly set
before being used:
•
The meter must be set to the correct standard for your
application.
•
The meter must be set for a specific frequency because
the averaging time in many standards is frequency
dependent. For example, IEEE C95.1-1999 specifies a
six minute averaging period for Controlled Environments
from 3 kHz to 15 GHz. Above 15 GHz, the averaging
period decreases to ten seconds at 300 GHz based on
a logarithmic function.