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Reference <br />u <br />To obtain the peak displacement, the BlastMate III integrates each wave segment of the entire <br />waveform between zero crossings, selects the largest, then divides the value by halt. Note that this <br />is not necessarily at the peak velocity of the waveform. <br />e. Peak Vector Sum (PVS) <br />The figure below displays three event waveforms. The figure illustrates the procedure of <br />graphically calculating peak vector sums. Measured magnitudes are tabulated for six different <br />times and represent velocities in each of the three axes. The vector sum represen[s the resultant <br />pazcicle velocity magnitude and is calculated by squaring and adding the magnitudes and taking the <br />square root. <br />PVS T= + Vz + Lz <br />where: <br />T = panicle velocity along the transverse plane <br />V = particle velocity along the vertical plane <br />L = panicle velocity along the longitudinal plane <br />The BlastMate III calculates the peak vector sum for each point of the sampled waveforms and <br />displays the largest value. Note that this is not necessarily at the peak velocity for an individual <br />waveform. <br />• <br />EVENT WAVEFORMS <br /> <br />TRANSVERSE VERTICAL LONGITUDINAL MAGNITUDE <br /> <br />T V L PEAK <br />VECTOR <br /> -0.34 -D.33 0.14 ' 0.494 <br /> 0.38 -0.47 0.38 0.774 <br /> 0.29 -0.31 ~ 0.51 0.663 <br /> -0.53 0.23 -0.31 ~ 0.655 <br /> 0.24 ~ 0.07 0.36 ~ 0.440 <br /> -0.23 -0.16 •0.15 0.318 <br /> <br />Figure 5.12 Calculating the Peak Vector Sum. <br />5.5.2. Sound Pressure <br />The BlastMate III calculates two sound pressure indicators, peak sound pressure and zero crossing <br />frequency. <br />a. Peak Sound Pressure (PSP) <br />The BlastMate III checks the entire event waveform and displays the largest sound pressure called <br />the Peak Sound Pressure (PSP), also refereed to as the Peak Air Over-Pressure. Results appear on <br />the BlastMate III display and in the Event Summary Report. <br />b. Zero Crossing Frequency (ZC Freq) <br />The Zero Crossing Frequency calculation for sound pressure is the same calculation used for <br />• ground vibrations. Please see above for a complete discussion. <br />BlastMate III Operator Manua] 5-11 <br />