Thank you to everyone who responded and clarified the issue, it is much 
appreciated.
Regards,
James


From: Pawson, James
Sent: 26 March 2015 15:02
To: [email protected]
Subject: [PSES] Quasi Peak - Length of Measurement Time for Final Spot 
Measurement?

Dear group,

When measuring emissions using a Quasi Peak detector are there any regulations 
or guidance concerning the amount of time one should dwell on a single 
frequency for a measurement?

I know it depends on the nature of the signal. In this case, the signal of 
interest results in a burst of emissions of a high duty cycle followed by a 
long period (i.e. several minutes) of low duty cycle activity. If I use a QP 
detector and measure for 1 second just as the burst happens then I would get a 
high QP reading. If I measure in the steady state period I would get a lower QP 
reading.

In this case, knowing the signals involves, would the intention to be to measure

1.       one full representative cycle of emissions i.e. the initial burst and 
the low duty period after
2.       during the maximum duty cycle only
3.       during the steady state only

I can imagine that the measurement difference between 1) and 3) in this case 
would be small as the level measured during the high duty period would have had 
time to decay down to the same level as the steady state due to the QP time 
constant.

I'm asking this question in the context of both EN 55022 and FCC 15.

Googling for "quasi peak measurement time" and similar phrases is not proving 
helpful

Many thanks
James Pawson

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