Triaxial Vibration Sensor

The Sensorbee Vibration Sensor (SB3641) is a triaxial vibration monitor designed for construction, blasting, and traffic vibration assessment. Measuring Peak Particle Velocity (PPV), Peak Component Particle Velocity (PCPV), peak frequency, and full FFT frequency spectrum across all three axes, this sensor delivers the data required for BS 7385-1 building damage assessment and BS 6472-1 human vibration evaluation. The IP67 weatherproof aluminium housing is built for long-term outdoor deployment on construction sites, near blasting operations, and at sensitive receptor locations.

How It Works

The SB3641 contains three accelerometers oriented along the X, Y, and Z axes, sampling vibration at 4096 Hz across a 1–100 Hz bandwidth. This high sample rate captures the full range of ground-borne vibrations generated by construction plant, piling, blasting, demolition, and road traffic. Raw accelerometer data is processed onboard to calculate Peak Particle Velocity (PPV) — the primary metric used in BS 7385-1 for assessing the risk of cosmetic or structural damage to buildings.

The sensor also outputs Peak Component Particle Velocity (PCPV) for each axis independently, peak dominant frequency, and full FFT frequency spectrum data. These parameters enable detailed vibration characterisation beyond the headline PPV value, supporting forensic analysis of vibration sources and frequency-dependent damage risk assessment.

Data is transmitted to the Air Pro 2 base station via Modbus RTU over the M8 extension port, and from there to the Sensorbee Cloud for real-time monitoring, alerting, and reporting.

Measurement Parameters

The SB3641 delivers the full set of vibration metrics used in standards-based assessment:

• PPV (Peak Particle Velocity) — the maximum resultant particle velocity across all three axes, the primary metric in BS 7385-1 for evaluating vibration impact on structures
• PCPV (Peak Component Particle Velocity) — individual peak velocity for X, Y, and Z axes, providing directional vibration analysis for identifying dominant vibration paths
• Peak Frequency — the dominant frequency component of the vibration event, critical for frequency-dependent damage threshold assessment under BS 7385-1
• FFT Spectrum — full frequency decomposition of the vibration signal, enabling detailed analysis of vibration sources and their spectral characteristics

The ±200 mm/s velocity range and 0.05 mm/s RMS noise floor provide the dynamic range and sensitivity needed for both high-energy blasting events and low-level traffic vibration.

Compliance With Vibration Standards

The SB3641 is designed to meet the measurement requirements of the standards used in environmental vibration assessment:

• BS 7385-1 — evaluation and measurement for vibration in buildings, providing guidance on vibration levels below which cosmetic damage to buildings is unlikely. The SB3641's PPV and frequency measurements directly support the damage threshold curves defined in this standard.
• BS 6472-1 — guide to evaluation of human exposure to vibration in buildings. The triaxial measurement and frequency analysis support the Vibration Dose Value (VDV) and weighted acceleration calculations used for human comfort assessment.

These standards are referenced in planning conditions, Section 61 consent agreements, and environmental impact assessments for construction and infrastructure projects.

Why Choose the Sensorbee Vibration Sensor

Vibration monitoring on construction sites has traditionally required expensive standalone instruments with separate data loggers, communications, and power supplies. The SB3641 integrates directly with the Air Pro 2, creating a unified dust, noise, and vibration monitoring station.

• Combined NDV monitoring — measure vibration alongside dust and noise from the same monitoring station, eliminating the need for separate vibration instruments and consolidating all environmental data in a single cloud platform
• Standards-compliant measurement — BS 7385-1 and BS 6472-1 compliance ensures the data meets the requirements of planning conditions and Section 61 consent agreements
• IP67 weatherproof construction — the aluminium housing with 5 mm base plate withstands rain, dust, and harsh outdoor conditions across the -30 to +60°C operating range, suitable for multi-year deployments
• Ultra-low power — 7 mW consumption allows the sensor to operate continuously from the Air Pro 2's solar-powered battery system without significant impact on station autonomy
• Real-time cloud alerts — set PPV trigger levels in the Sensorbee Cloud and receive instant notifications when vibration thresholds are approached or exceeded, enabling proactive response before limits are breached

Installation

The SB3641 connects to the Air Pro 2 via the M8 extension port using the included 2.5 m cable. Place the sensor on a solid surface or mount it using the 5 mm aluminium base plate. For ground vibration monitoring, position the sensor on a firm, level surface with good ground coupling — a concrete slab, structural floor, or purpose-made ground mount.

The Air Pro 2 detects the vibration sensor automatically via Modbus RTU and begins recording and transmitting vibration data to the Sensorbee Cloud. No configuration, calibration, or firmware updates are required at the time of installation.

For buildings or structures where internal vibration assessment is needed, extension cables allow the sensor to be placed at the assessment position while the Air Pro 2 remains at its outdoor mounting location.

Applications

• Construction site vibration monitoring — continuous PPV monitoring for BS 7385-1 compliance during piling, excavation, compaction, and demolition operations, with real-time threshold alerts to site managers
• Blasting vibration assessment — capture peak vibration from blasting events with the ±200 mm/s range and 4096 Hz sample rate, providing PPV, PCPV, and frequency data for blast impact reporting
• Traffic vibration surveys — measure vibration from road and rail traffic at sensitive receptor locations, supporting environmental impact assessments and planning applications for transport infrastructure
• Human comfort assessment — BS 6472-1 compliant measurement for evaluating the impact of construction or operational vibration on building occupants at residential and commercial properties
• Heritage and sensitive structures — monitor vibration at historically significant or structurally sensitive buildings where lower damage threshold limits apply under BS 7385-1 guidance
• Tunnelling and underground works — continuous vibration monitoring during tunnel boring, shaft sinking, and underground construction activities where ground-borne vibration must be managed within strict limits

Frequently Asked Questions

Does the vibration sensor meet BS 7385-1 requirements?

Yes. The SB3641 provides PPV and peak frequency measurements in the 1–100 Hz bandwidth specified by BS 7385-1 for evaluating vibration impact on buildings. The triaxial measurement covers all required directional components.

How is the sensor positioned for ground vibration monitoring?

Place the sensor on a solid, level surface with good ground coupling — typically a concrete slab, structural floor, or building foundation. For external ground monitoring, a purpose-made ground mount or sand bag coupling may be appropriate depending on ground conditions.

What is the maximum vibration it can measure?

The SB3641 has a velocity range of ±200 mm/s, which comfortably covers the range of construction and blasting vibrations encountered in typical monitoring applications. This range exceeds the damage threshold limits defined in BS 7385-1.

Can I use it without the Air Pro 2?

The SB3641 communicates via Modbus RTU and can be connected to any Modbus-compatible data logger or controller. However, integration with the Air Pro 2 provides the simplest path to cloud connectivity, real-time alerts, and combined environmental monitoring.

How long is the cable?

The SB3641 ships with a 2.5 m cable and M8 connector. Extension cables are available from Sensorbee for installations where the sensor and base station require greater separation.