Dynalyzer – High Voltage Unit
OPERATION MANUAL
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Definitions
kVp:
The FT algorithm computes kVp using the Fourier Transform of a selected region of the kV waveform. For
these selected samples, the major ac components are combined with the biased-average kV to estimate the
effects of ripple, leading to a measurement of the “average” peak voltage. This averaging process suppresses
the effects of noise, which can result in serious errors for routines that use only small data samples.
Average kV:
The average value of kV in the region of interest above an adaptive kV threshold.
PPV:
The Practical Peak Value (PPV) mode computes a weighted average of the kV waveform in the region of
interest, with weighting toward higher-kV values, employing the algorithm of Kramer, Selbach and Iles.
Time:
The width of the region of interest.
mA:
Average mA is mAs divided by the width of the region of interest.
mAs:
mAs is the sum of mA values during the region of interest.
Region of Interest:
After the exposure, Accu-Gold Excel analyzes a selected portion of the exposure. The region of interest is the
area of the pulse determined by the threshold settings. After the pulse is detected, the software post-processes
the data and displays the results based on this region of interest.
Addendum
Relevant Zero: When measuring the output on high-voltage machines it can take several minutes for the
generator to settle. If the measure sequence is initialized without waiting, the system will produce errors as it is
attempting to re-zero.
Accu-Dyn+ Template: This template accommodates uninterrupted measuring without a wait period by
establishing a zero on the initial start. This value will be used for all other measurements.
Usage: When clicking “Start” or Ctrl + Shift + R to initialize the measure sequence for the first time the first
output cell will automatically turn green then immediately stop. Once it has stopped, “Zero” has be established.
You can now start the measure sequence again and collect data.
Digital Display and Accu-Dyn+ Comparison: Differences between the Accu-Dyn+ and Digital Display may be
observed when used in parallel. The Digital Display measures kVp by finding the maximum voltage (including
noise) whereas the Accu-Dyn+ kVp ignores noise spikes riding the kV waveform. The Digital Display measures
mAs and then calculates the mA whereas the Accu-Dyn+ measures the mA waveform. For making low mA
measurement (<100 mA) it is recommended that the Accu-Dyn+ template be reset prior to exposure.
