Mode 2 averaging – NARDA 8718B User Manual

Page 62

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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.

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