Fluke Biomedical 4000M+ - Manual (Page 40)

Victoreen 4000M+
Operators Manual
B-6
Calculation of kV Waveform
The kV waveform may be reconstructed via calculations performed on the radiation waveforms. The
pseudo code for producing all three available waveforms is as follows:
Use the D command to acquire a 4000M+ data dump.
Use the F command to read the FILTER.
If TIME >100 ms, then
Set NPOINTS to 757,
Else,
Set NPOINTS to Int(TIME(sec)/1.32E-4)).
Use the W command to fill the two buffers, AWAV and BWAV with channel A and channel B data,
respectively. The number of points acquired should be NPOINTS.
Use the C command to read the floating-point value, slope, and offset.
Set BMAX to 0.
For J = 1 to NPOINTS,
If BWAV(J) > BMAX, then
BMAX = BWAV(J);
Set THRESHOLD to BMAX/16.
If THRESHOLD < 255, then
Set THRESHOLD to 255.
Set LO to low limit for filter setting used.
Set HI to high limit for filter setting used.
Set LORAT to (In(0.9 * LO) – OFFSET1)/SLOPE.
Set HIRAT to (In(1.05 * HI) – OFFSET1)/SLOPE.
For I = 1 to NPOINTS,
If AWAV(I) <> 0.0 then,
Set R to BWAV(I)/AWAV(I);
Else,
Set to 0.0.
If R < LORAT or R > HIRAT or BWAV[I] < THRESHOLD, then
Set KWAV(I) to 0.0;
Else,
Set KWAV(I) to exp(R * SLOPE + OFFSET1).
end.
At this point, there are three arrays, AWAV, BWAV and KWAV, representing the three available
waveforms, lightly filtered, heavily filtered, and kV, respectively. Each array element corresponds to 132
microseconds of waveform.