FiberStrike LCM-940 Pedestrian Sensing Platforms

A patented fiberglass grid walking platform with embedded FBG sensors that detects the presence of a person standing on it. Platforms multiplex over one fiber and report to remote monitoring equipment.

Technical overview

Weight depressing the platform surface strains an internal FBG, shifting its reflected wavelength longer; the minimum trigger weight quoted by CEL is 1 kg. Platforms contain no electronics, need no power and radiate no signal, so they cannot be bypassed without detection. Standard sizes run 2 or 4 ft wide by 2 to 12 ft long in 2 ft increments, 1 inch thick, on a slip-resistant fiberglass-reinforced resin grid rated IP-66 and ASTM E84 Class 1. Data can be presented through CEL's IntelliOptics software, which supports a virtually unlimited quantity of platforms and offers cloud hosting.

Sensing Distributed Sensing

Features

Contains no electronic components, requires no electrical power and radiates no signals
Cannot be bypassed without detection
Multiple platforms may be multiplexed over a single optical fiber while remaining individually addressable
May be located tens of kilometers distant from the monitoring equipment
Leverages existing standard communications fiber infrastructures
Custom intermediate widths, lengths and grids available on special order
Data may be presented via IntelliOptics software with a cloud hosting option

Specifications

Specifications
Parameter	Value
Sensing principle	FBG strain change causes wavelength shift
Actuation method	Weight depresses platform surface
Sensitivity	1kg (7 oz.) weight minimum (recorded exactly as published by CEL; the two units do not agree) kg
Wavelength shift direction	Wavelength shifts longer when weight is applied to platform
Mechanical life	10,000,000 cycles minimum cycles
Operating temperature range	-25 C to +70 C (-13 F to +158 F) degC
Insertion loss	0.25dB per 2 ft (61cm) square dB
Wavelengths	FBGs at >=5nm intervals, selected based on application nm
Reflectivity	>70 %
FWHM (-3dB)	0.3nm (apodized grating, SLSR >15%) nm
Dimensions - Width	2 ft or 4 ft (61cm or 122cm) ft
Dimensions - Length	2 ft (61cm) to 12 ft (365cm) in increments of 2 ft (61cm) ft
Dimensions - Thickness	1 in (2.54cm) in
Grid squares	on 1.5 in (3.8cm) centers in
Mounting	Supported at perimeters, also at intermediate points as required by span
Weight load capacity - maximum recommended	1350 lb/ft2 (6600 kg/m2) uniformly distributed load lb/ft2
Weight load capacity - ultimate	6750 lb/ft2 (33000 kg/m2) uniformly distributed load lb/ft2
Protection rating	IP-66 per IEC 60529
Platform material	Fiberglass-reinforced resin grid, slip-resistant grit surface, non-conductive
Fire retardant rating	Class 1, flame spread rate <=25 per ASTM E84
Platform material color	Yellow standard; other colors available on special order
Cable type	Aramid reinforced pigtail, 3mm diameter jacket (two pigtails per platform unit) mm
Cable length	1.5m +/-10cm (60 in +/-4 in) standard m
Cable tensile load	Maximum 500N (110 lb) during installation, 300N (70 lb) operating N
Cable bend radius	Minimum 29mm (1.14 in) during installation, 25mm (1.0 in) operating mm
Fiber type	SMF-28 compatible
Fiber coating	Polyimide
Connection method	Fusion splice standard; optional APC connectors on special order
Average system response time to an event	1.5 s