The improved impedance probe uses digital frequency synthesis and, due to the fast sweep time of the instrument, allows for a good spatial resolution (130 m) together with high accuracy (1.5%).
Based on the increase of storage modulus with sweep time, the presence of reactive chain ends were proved, promoting chain growth in either polyamide and interchange reaction in binary blend at high temperature.
In Figs 3 and 4 the spectrum analyser was set to zero frequency span and centred at 7 MHz where the signal-to-noise ratio of the detection is maximum, with a sweep time ranging from 1 s to 20 s depending on the type of measurement.
For instance, the sweep time of FSVR is listed as 100 μs which is the shortest sweep time the device can achieve, and the same applies to the sweep time of the USRP in continuous FFT mode.
For the continuous FFT mode, the sweep time is equivalent to the sampling time.
The recurrence frequency was 19.3 Hz (bandpass, 150 1500 Hz; sweep time, 10 ms).
To a certain extent, users can lower the sweep time to increase the time resolution.
When measuring the PSD, the time resolution depends on the sweep time.
The time needed for the front-end to scan the entire frequency span is called the sweep time.
In the spectrogram mode, the number of combined FFT shots is defined by the parameter sweep time.
Frequency sweep time interval was set to 26 seconds, corresponding to an increase rate of about 1.7 Hz per second.
