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<br />Memory Management: The instrument operator should know the memory or record <br />capacity of the seismograph and ensure that adequate memory is available to store the <br />event data from the blast(s) planned during that operating day. <br />9. Waveform Data: Instruments shall be set to save full waveform data for all monitored <br />blast and digitally saved event files shall contain this data for use in further analyses if <br />needed. <br />10. Instrument Setup Time: Equipment operators should allow ample time for proper setup <br />of the seismograph, transducers and microphones. At least 15 minutes of time should be <br />allotted for each setup location. <br />11. Securing cables: In order to prevent false triggering caused by wind-blown cables, the <br />operator should secure suspended or freely moving cables from the wind or other <br />extraneous sources. <br />Part II. Ground Vibration Monitoring <br />A. Sensor Placement <br />The sensor should be placed on or in the ground on the side of the structure towards the blast. A <br />structure can be a house, pipeline, telephone pole, etc. Measurements on driveways, walkways, <br />and slabs are to be avoided where possible. <br />1. Location relative to the structure: The sensor should be placed within 10 feet of the <br />structure or less than 10% of the distance from the blast, whichever is less. <br />2. Soil density evaluation: The operator should avoid placing velocity transducers in loose <br />or low-density soils. The density of the ground should be greater than or equal to the <br />sensor density. <br />3. Sensor Level: Transducers should be placed so they are level or nearly level. <br />4. Sensor Orientation: Sensor blocks should be oriented so the arrow indicating the <br />longitudinal direction is aimed at the blast location. <br />5. Monitoring when Access to Nearest Structure is not Accessible: Where access to a <br />structure is not available, the transducers should placed at the accessible location closest <br />the structure of concern and in line with the blast. <br />B. Sensor coupling <br />Sensor Coupling Methods: Based on expected acceleration determined from Chart 1, to <br />avoid decoupling errors, the operator shall use the following methods to couple <br />vibration transducers to the ground or structure. <br />a. Less than 0.2 g: No burial or attachment is necessary.