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Charlotte Stonestreet
Managing Editor |
Editor's Pick
Seismic safety switch
24 March 2016
Part of Sensonic's range of seismic monitoring protection systems for the nuclear industry, the SA-3 seismic safety switch provides triaxial vibration detection and is used to protect vulnerable structures from ground borne vibration events. It incorporates a range of safe shutdown options, depending on the application.

The SA-3 model features three high-integrity low-noise piezoelectric seismometers positioned at 90º to each other along with the associated alarm circuitry housed within a robust weatherproof painted steel enclosure.
It is seismically qualified to IEEE-344 (Standard for Seismic Qualification of Equipment for Nuclear Power Generating Stations) and utilises technology operationally proven in harsh environments. The switch operates on seismic events and when the signal from any axis exceeds the pre-set alarm level, the alarm relay is activated.
The sensors consist of a unique system of matched piezoelectric elements arranged in a ‘reciprocal’ configuration providing a functional test capability. Application of a 1Hz signal to the calibration crystal element mechanically excites the measuring elements resulting in a defined signal output which can be used to perform a full loop check of the seismic switch. Such a facility is essential for applications where the switch is located in a hazardous area and requires full-proof testing on a regular basis.
As well as the usual seismic and EMC approvals the SA-3 switch is available for functional safety applications up to SIL-2 and can also be provided in an explosive-proof housing for intrinsically safe applications.
- Using the right condition monitoring system
- Sensonics Achieves ISO 45001:2018 Certification
- Critical protection
- Fully integrated proximity probes
- Advanced display options
- Sensonics expands calibration & site support services
- Cost-effective vibration measurement for smaller machinery
- Taking machinery protection to the next level
- High-integrity overspeed protection
- Proximity probe holders for hazardous areas
- Heavy Duty Use
- Motion Control
- Looks Good On Paper
- Better Than 1% Set Point Repeatability
- Intelligent Biogas Analysers Control Desulphurisation
- Heavy Duty Guarded Footswitch
- Displays & Controls PH & ORP Values
- Control & Isolation Products Brochure
- Switching Technology
- Custom Capacitive Interface Panels