Importance of dwell (or measurement time) in capturing random bursts of EMI
时间：03-25
整理：3721RD
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My issue is related with the setting of measurement time (MT) on a EMI receiver with the aim to capture occasional frequencies of EMI that appear, perhaps, only once and in random manner, not periodically, during a device's switch on event.
Studies say that dwell (or measurement time, i.e. MT) per frequency sample has to be long enough (i.e. several ms) in order not to miss a signal from being picked up during a frequency scan. However, what does not make sense to me with this is that by applying a long MT, you are effectively reducing the chance to observe a frequency higher up on the spectrum, since the EMI receiver will be 'delayed' with the sweep of the lower end of the spectrum (as an example). My understanding is that someone must initially use the shortest possible MT in order to ensure that the EMI receiver scans a given spectrum as fast as possible in order to maximise the chance of picking up a strong frequency which may appear anywhere and at anytime. Is this a logical statement? In all cases, I assume the usage of a peak detector with maximum hold.
Thanks.
Studies say that dwell (or measurement time, i.e. MT) per frequency sample has to be long enough (i.e. several ms) in order not to miss a signal from being picked up during a frequency scan. However, what does not make sense to me with this is that by applying a long MT, you are effectively reducing the chance to observe a frequency higher up on the spectrum, since the EMI receiver will be 'delayed' with the sweep of the lower end of the spectrum (as an example). My understanding is that someone must initially use the shortest possible MT in order to ensure that the EMI receiver scans a given spectrum as fast as possible in order to maximise the chance of picking up a strong frequency which may appear anywhere and at anytime. Is this a logical statement? In all cases, I assume the usage of a peak detector with maximum hold.
Thanks.