Quarries

Quarrying is the process of extracting rock—known as aggregate—from the ground. These materials are essential for producing asphalt, cement, and other construction products used in homes, roads, and infrastructure projects. Blasting is a critical first step in this process, allowing large volumes of rock to be efficiently broken and removed.  When a blast occurs, two primary effects may be noticed by nearby homeowners and building occupants: ground vibration and air overpressure. The detonation of explosives generates a sudden release of energy, creating vibration waves that travel through the ground and compression waves that move through the air. Depending on the size and design of the blast, these effects can be felt miles away.  If levels exceed safe limits, vibrations may crack drywall or impact structural integrity, while excessive air overpressure can rattle or even break windows. Monitoring and controlling these effects is essential to protect surrounding properties and maintain community confidence. 

Industry standards have been established to define safe limits for vibration and air overpressure generated during quarry activities such as blasting.  The Instantel monitoring system pairs the Micromate Plus unit with a versatile range of sensors to simultaneously capture vibration, noise, and air overpressure, with real-time data reporting powered by Vision II software. With Live Data—a Vision II feature—blast events can be viewed as they occur, enabling quick, proactive responses and helping ensure continued compliance with regulatory guidelines.  For deeper insight and optimized blast performance, THOR Advanced analysis software offers advanced tools and high-frequency sampling, allowing teams to evaluate waveforms in detail. This level of analysis supports more efficient blasting practices that minimize community impact, protect the environment, and keep projects on schedule.  

Regulatory Compliance  

In quarry blasting, monitoring can take place in two zones: near-field, which occurs close to the blast source, and far-field, which is conducted at greater distances. The monitoring zone determines the type of equipment best suited for the project and the type of data required.  

Far-Field Monitoring  

Far-field monitoring is typically performed near property boundaries to ensure regulatory compliance and protect nearby homes and buildings. When blasting occurs, it’s natural for the public to become concerned if they feel vibrations—such as a china cabinet rattling—even when levels are within safe limits. The Micromate Plus, paired with Vision II software, provides simultaneous monitoring of vibration, noise, and air overpressure, with real-time event visibility. This allows operators to prevent exceedances before they happen, produce required regulatory reports, and keep all stakeholders informed and confident in the blasting process.

Blast Design (Near-Field) Monitoring

Near-field monitoring takes place close to the blast source, where vibration amplitudes are highest, waveforms are more complex, and high-frequency energy is most pronounced. Instruments used in this zone must withstand intense motion while capturing detailed data to evaluate blast design and maximize production efficiency.  As each hole in a blast pattern detonates, the resulting vibration waves interact with one another. A well-designed blast leverages this interaction by adjusting timing delays and spacing between holes and rows. Proper timing helps localize energy, improve fragmentation, and reduce the need for additional drilling or secondary blasting.    

Every hole generates its own vibration wave. By measuring the velocity of these waves, engineers can calculate the optimal delay between detonations or the required distance between holes and rows to achieve the desired blast performance.  Because vibrations diminish rapidly with distance, near-field monitoring requires a geophone capable of accurately recording high-energy motion close to the blast. The Instantel High Frequency Geophone measures vibrations from 30 Hz to 1000 Hz, ensuring all critical frequency content is captured. This data is recorded using the Minimate Pro series and then reviewed and analyzed in THOR Advanced software for deeper insight into blast effectiveness.  

Instantel monitoring equipment is engineered for durability and long-term deployment, making it ideal for permanent installations over the duration of a quarry project. Data captured by the system is transmitted in real time and accessible through Vision II, our secure, cloud-based platform, from any internet-connected device.  

Vision II provides full remote device management capabilities, allowing users to program or adjust monitoring schedules, check battery and memory status, retrieve recorded events, and perform firmware updates—all without accessing the device onsite. For projects requiring continuous oversight, Vision II supports 24/7 automated data sharing. Devices can be configured to record in Histogram-Combo mode continuously, capturing background vibration levels while still generating detailed waveform reports for events that exceed defined trigger thresholds. The histogram event reports deliver peak particle velocity (PPV) values at set intervals, ensuring comprehensive vibration profiling throughout the monitoring period. 

For more advanced monitoring, the THOR Advanced desktop platform supports high-frequency sensors capable of capturing up to 65,536 samples per second. This higher-resolution data reduces uncertainty and makes it easier to distinguish between blast-induced vibrations. Because delay intervals between charges are often only milliseconds, more precise velocity measurements significantly improve the accuracy of distance and timing calculations.

With THOR Advanced, you can perform detailed post-processing of recorded event data. THOR Advanced allows you to place markers on the waveform to identify the exact moment each hole detonates and view the corresponding particle velocity at that point in time. Its advanced analysis tools enable you to perform frequency analysis and truncate waveforms to isolate vibrations produced by individual holes. You can also overlay the planned blast timing pattern onto the recorded data for direct comparison. This makes it easy to verify whether each hole fired according to the blast design and to diagnose any timing or sequencing issues.    

All Instantel systems are designed for remote configuration and autonomous operation, backed by rigorous manufacturing standards and certified calibration for maximum reliability and data integrity.

With THOR Advanced desktop software, you can perform detailed post-processing of recorded event data. THOR allows you to place markers on the waveform to identify the exact moment each hole detonates and view the corresponding particle velocity at that point in time. Its advanced analysis tools enable you to perform frequency analysis and truncate waveforms to isolate vibrations produced by individual holes. You can also overlay the planned blast timing pattern onto the recorded data for direct comparison. This makes it easy to verify whether each hole fired according to the blast design and to diagnose any timing or sequencing issues.