92
Revision 00 EN - 01/2021
HP-MSM-HB
35,0(6
Pulse frequency
Per
cent change in energy for
n-1 pulses
Fig. 22.3:
Percentage of change in the detected energy when exactly one pulse is left out, in correlation with the pulse
frequency
Tab. 22.1 on page 91 Shows the number of detected pulses during the maximum integration time (186
ms) and during an integration time of 1 ms for various pulse frequencies.
Quantization with low pulse frequencies is clearly illustrated in the column for the 186 ms integration time.
While 1 860 pulses are detected at a pulse frequency of 10 kHz, at 10 Hz there is only one or no more than
two.
If the signal level is too high during a measurement at 10 Hz pulse frequency and the software tries to ad-
just the integration time, there are only three possible results. The energy application for a measurement
remains the same, it decreases by 50 %, or it drops to zero. These increments are less significant at a pulse
frequency of 10 kHz. This correlation is shown in general terms in Fig. 22.3 on page 92. It is important to
recognize that, starting from a pulse frequency of 500 Hz, the minimum jump when the integration time is
shortened amounts to 1 %.
Small pulse frequencies aren’t the only thing that will cause quantization though. If the pulse energy is very
high and it isn’t possible to further increase the attenuation, the integration times will be smaller. In Tab. 22.1
on page 91, an integration time of 1 ms is added to the maximum integration time. In this case, a pulse
frequency of 500 Hz is not sufficient in order to pretty much continuously control the energy application for
each measurement through integration time control.
