Vibration Criterion (VC) Curves
Monitoring vibration impact on sensitive equipment has traditionally required specialist instruments, bespoke consultant analysis, and complex reporting. With SiteHive, you can now monitor compliance against Vibration Criterion (VC) Curves in real time, with automatic alerts, dashboard visualisation, and data export built in.
When should I use VC Curve monitoring?
What are VC Curves?
VC Curves (Vibration Criterion Curves) are an internationally recognised standard for assessing the impact of vibration on sensitive equipment and spaces such as hospital operating theatres, university research labs, electron microscopes, and data centre equipment.
Rather than a single threshold, there are multiple curves, each representing a level of sensitivity. The lower the letter, the more stringent the limit. Vibration is measured as root-mean-squared (RMS) velocity across 1/3 octave frequency bands from 1 Hz to 100 Hz.
VC Curve |
RMS Velocity Limit |
Typical application |
|---|---|---|
VC-A |
50 µm/s |
Standard laboratories, offices |
VC-B |
25 µm/s |
Hospital operating theatres, sensitive labs |
VC-C |
12.5 µm/s |
Electron microscopes, research equipment |
ℹ️ SiteHive currently supports monitoring against VC-A, VC-B, and VC-C. VC-D and VC-OP are not currently supported. Your project specification or environmental management plan will confirm which VC Curve applies to your site.
What we offer
Real-time, continuous monitoring
The SiteHive Hexanode Vibration Device measures RMS velocity across 1/3 octave bands and uploads data continuously to the SiteHive Enviro Pro dashboard, with no manual data collection required.
Dashboard visualisation
View broadband RMS velocity over time plotted directly against your selected VC Curve threshold, all in one place.
Threshold alerts
Set a VC-A, VC-B, or VC-C threshold and receive a notification within one minute of an exceedance, by email or SMS.
Events and investigation
Every exceedance is automatically logged as an event, with a timestamp, peak level, and waveform detail so you can investigate causes and demonstrate compliance management.
Data export
Download CSV reports containing broadband and 1/3 octave band data for any time period.
ℹ️ VC Curves monitoring is an Enviro Pro feature. To get it enabled on your site, reach out to your BDM or contact support@sitehive.com.
How it works
On the device
The SiteHive Hexanode Vibration Device records high-frequency raw vibration data.
It calculates RMS velocity across 1/3 octave frequency bands from 1 Hz to 100 Hz.
Data is integrated over 1-minute periods (with 1-second resolution) and uploaded to the cloud.
In SiteHive Enviro Pro
Your broadband RMS level is displayed on the dashboard, plotted against your chosen VC Curve threshold for instant compliance assessment.
Alerts fire automatically when the broadband level exceeds your configured threshold.
💡 Tip: The SiteHive Hexanode is capable of measuring to VC-C from 2 Hz upward, covering the compliance requirements for the vast majority of construction projects near sensitive environments.
Data Display and Reporting
Setting a threshold
To receive notifications when the vibration level exceeds your selected threshold, set up a rule in Settings > Rules & Notifications.
CSV export
Download your data from the Reporting section of the dashboard. The export includes broadband RMS velocity over time and 1/3 octave band data for the selected period.
PDF reporting: Periodic PDF reports for VC Curves are coming soon. Use CSV export in the meantime.
When should I use VC Curve monitoring?
VC Curve monitoring is typically used when construction or industrial activities occur near vibration-sensitive equipment.
Common applications include:
Hospitals with MRI, CT or imaging equipment
Research laboratories using microscopes or precision instruments
Semiconductor manufacturing facilities
Data centres and sensitive electronic environments
Universities and research facilities
If your project specification, environmental management plan or client requirements reference VC Curves, this feature can be used to assess compliance against the nominated VC Curve threshold.
Handy Links
Hive Article - Product Update: VC Curve Monitoring for Sensitive Equipment
For help setting up VC Curves monitoring, contact support@sitehive.com