Function Description - Honeywell SC105 Installation & User Manual

Function Description

3 Function Description
Function Criteria
Detection Parameters
The detection function of Mini-Seismic Vibration Detector SC105 is based on the structural
vibrations generated on the protected surfaces upon an attempt to break through the physical
barriers.
Vibrations detected comprise four important parameters:
These parameters differ between real attacks and "normal" background vibrations and will be
detected and analyzed by the detector before an alarm is triggered. The characteristics below
represent signals that can be detected by Detector SC105:
Alarm Criteria
In Detector SC105, the signals detected will be analysed by several parallel software detection
modes with specific algorithms for detection of known attack methods and tools, which can be
described as below:
The signal from the sensor is fed to the signal conditioning block and further to the micro
controller for evaluation. An alarm signal will be sent to the output alarm block when a criteria with
signal strength, frequency spectra and signal duration is achieved.
Function Modules
Sensor Element
Mini-Seismic Vibration Detector SC105 includes a sensor element that converts mechanical
vibrations into electrical signals providing a non resonant flat frequency response for genuine
signal analysis, which is used for detection of structural vibrations caused by attacks against the
protected surface. These signals will be analyzed in different software detection modes.
Signal Conditional Block
The electrical signal that sensor converted is fed to the signal conditional block that adapts the
signal for further analysis. It also contains circuits for supply voltage and temperature supervision
(see
SC113.
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
signal strength (amplitude)

signal frequency (spectra)

signal duration

structure of duration

Signals with very high amplitude and short duration, which can be generated by explosives.

Signals with medium to high amplitude and medium to long or intermittent duration, which
can be generated by mechanical demolition tools.

Signals with wide frequency spectra, low amplitude and long duration, which can be
generated by thermal attacks.

The low level detection mode is designed to recognize low to medium amplitude signals
with long duration, like those caused by a thermic lance, oxy-arc or acetylene torch.

The medium level detection mode is designed to detect medium to high amplitude
signals as caused by mechanical demolition, such as electric power tools.

The high level detection mode is designed to detect very high amplitude and short
duration signals as caused by explosives.
on page 4). This block also generates test signals for the Test Transmitter
Alarm Criteria