Appendix D: Blasting Seismograph Standards

PERFORMANCE SPECIFICATIONS FOR BLASTING SEISMOGRAPHS

International Society of Explosives Engineers (ISEE) – Standards Committee Members

Chairman, Kenneth K. Eltschlager, US Office of Surface Mining Reclamation and Enforcement
Douglas Bartley, DBA Consulting
Steven DelleDonne, Simpson Gumpertz & Heger Inc.
Alastair Gorgas, Davey Bickford Canada, Inc.
Alan Richards, Terrock Consulting Engineers, Inc.
Douglas Rudenko, Vibra-Tech Engineers, Inc.
Mark Svinkin, Vibracontol
Robert Turnbull, Instantel
Randall Wheeler, White Industrial Seismology
Russel Lainano, John Wingard, Vibronics Inc.

Disclaimer

These performance specifications are intended to provide design guidelines for blasting seismograph manufacturers. It is incumbent on the blasting seismograph operator to evaluate field conditions, identify the appropriate field criteria and select the proper blasting seismograph for the field application. The operator is responsible for documenting the field conditions and setup procedures in the permanent record for each blast.

Preface

Blasting seismographs are used to establish compliance with regulations that have been established to prevent damage to public and private property. The disposition of the rules is strongly dependent on the accuracy of ground vibration and air overpressure data. One goal of the ISEE Standards Committee is to ensure consistent recording of ground vibration and air overpressure between all blasting seismographs.

Part I. General Guidelines

Blasting seismographs are deployed in the field to record the levels of blast-induced ground vibration and air overpressure. Accuracy of the recordings is essential. These guidelines define the manufacturers' responsibilities when building blasting seismographs for surface field use to measure ground vibration and air overpressure that will be suitable to meet requirements specified in Title 30 Bureau of Mines RI 8507 and RI 8485. The blasting seismograph should be deployed in the field according to the ISEE "Field Practice Guidelines for Blasting Seismographs" (ISEE 2009). The following specifications are considered minimum:

Parameter	Specification
Digital sampling rate	1000 samples or greater, per channel
Operating temperature range	10 to 120°F (-12 to 49°C)
Electrical cross-talk	Less than 2% of the input signal appears on any other channel

Part II. Ground Vibrations Measurement

Ground vibration sensor response characteristics should conform to the following maximum values:

Parameter	Specification
Frequency range	2 to 250 Hz, within zero to ±3 dB of an ideal flat response
Accuracy	±5% or 0.5 mm/sec (0.02 in/s), whichever is larger, between 4 and 125 Hz.
Phase response	Phase shall between 2.5 Hz to 250 Hz shall not cause an error of more than 10% to the maximum absolute value of two superimposed harmonic vibrations.
Cross-axis	Less than 5% of the actual value indication on either of the mutually perpendicular channels when excited at the natural frequency of the sensor or 10 Hz for sensors with a natural frequency greater than 250Hz.
Density of sensor	~1763 lb/ft³ (should be reported for user consideration).

Part III. Air Overpressure Measurement

Air overpressure microphone should conform to the following maximum values:

Parameter	Specification
Frequency range	2 to 250 Hz, ±3 dB at 2 and 250 Hz, ±1dB
Accuracy	±10% or 0.04 millibars (and between 4 and 125 Hz.
Microphone seismic sensitivity	Microphone response to a mechanical vibration of 50 mm/s (2 in/s) at 30 Hz, from any angle, must be less than 40 dB below the maximum microphone output, or 106 dB whichever is lower.

Part IV. Calibration

To ensure proper operation, blasting seismographs should be calibrated annually by a facility authorized by the manufacturer.

Parameter	Requirement
Frequency	Annually
Traceability	Calibration equipment accuracy must be traceable to National Institute Standards and Testing, National Research Council or equivalent.
Certificate	Issued with each calibration and signed by the authorized service representative.
Documentation	Send along with input and output values at each frequency. Provide sufficient documentation of measured frequency response characteristics to test with Part II and III.

Part I. General Guidelines (continued)

Ground Vibration Sensor... Calibration must be of the assembled sensor. Component calibrations of individual sensors are not appropriate.

Part V. Measurement Practices

Measurement practices are specified in the ISEE Field Practice Guidelines for Blasting Seismographs. Some field needs are specific to an operator, an application, or a region and may be requested by a customer. For example, use under arctic-type conditions requiring good performance at low temperatures or extended frequency ranges such as might be of concern for close-in construction blasting.

Other performance capabilities related to specific needs may include:

Dynamic range (smallest to highest usable measurement)
Resolution
Trigger levels and options (vibration, air overpressure or both)
Recording duration (per event)
Memory or record capacity (number of events)
Nature of display and recording (tape copy, LCD, downloading, etc.)
Mounting options (transducer attitude, orientation, etc.)

It is the responsibility of the operator to confirm that the instruments selected for measurement of ground vibrations and air overpressure due to blasting under conditions not specifically covered by standard, has performance characteristics, and has been properly calibrated, to record data consistent with the tolerances described herein.

References

American National Standards Institute. Classifications to be Specified for Seismic Transducers, ANSI S2.46-1989, B, 2005.
Detection Institute for Nonmeng (DIN). Mechanical Vibration and Shock Measurement, DIN 45669-1, 1995.
International Society of Explosives Engineers. ISEE Field Practice Guidelines for Blasting Seismographs, 2009.
Siskind, D. E., Staechura, V. J., Stagg, M. S., Kopp, J. W. Structure Response and Damage Produced by Airblast From Surface Blasting, US Bureau of Mines Report of Investigations 8485, 1980.
Siskind, D. E., Stagg, M. S., Kopp, J. W., Dowding, C. H. Structure Response and Damage by Ground Vibrations From Mine Blasting, US Bureau of Mines Report of Investigations 8507, 1980.
Staechura, V. J., Siskind, D. E., Engler, A. J. Airblast Instrumentation and Measurement for Surface Mine Blasting, US Bureau of Mines Report of Investigations 8508, 1981.
Stagg, M. S., Engler, A. J., Measurement of Blast -Induced Ground Vibrations and Seismograph Calibration, US Bureau of Mines Report of Investigations 8506, 1980.