Wireless Monitoring System

WiSenMeshNET 1700 Displacement Temperature Sensor Node

This internally powered dual sensor node allows remote measurement of dynamic distance displacement associated to track voiding and critical rail temperature (CRT) monitoring utilising a magnetic probe which measures the rail skin temperature.

The spring-loaded displacement sensor has a measurement range of 50mm with range models of 100/150 & 200mm also attainable. The working principle is that the sensor becomes active through the breaching of a user defined vibration threshold trigger from an approaching train. The sensor then measures the track under load during the train passage at a sample rate of 33Hz and remotely reports the maximum, minimum and average deflection (Rail Swing) over this time period. The sensor can also be set to measure is static mode with readings attained at defined time intervals.

The magnetic NTC thermistor temperature sensor is typically magnetically attached to the rail skin web using the 3kohm sensor model able to record track temperatures from -40°C to +85°C.

The sensor node is installed and clamped to the underside of the rail web between the track and the ballast, with the reference plate for the displacement sensor leaned to the ballast and set to the desired initial starting range value such that track voiding deflection is measured for compression and/or expansion.

The node includes an integrated internal radio antenna which then transmits data wirelessly to a site based SmartGateway before data is pushed to the internet for visualisation display and alerting.

The battery lifespan is up to 9.5 years at hourly readings.

WiSenMeshNET Dynamic Displacement & Temperature Sensor Node System - 1700

The unit is combined with: A. External displacement sensor, for railway track vertical movement or crack development; B. External temperature sensor, for railway track variation monitoring. A vibration threshold trigger value can be set on a node switch, so that once the vibration threshold is reached by any object, such as a train passes by, a node can sample at 33Hz rate, and report to a gateway of maximum, minimum, average over a time interval.

WISENMESHNET® Displacement Sensor Node
Basics
Battery Power		Qty. x 1 (3.6V Lithium primary D-Cell ER34615)
Accuracy Stop Voltage		2.7VDC
Mesh Stop Voltage		2.1VDC
Battery Connection		Standard Aluminium Battery Holder
Working Current		Max. 28mA (Typ. 9mA) @ Mode=0
Alternative DC Input		3.6VDC
Local Storage		Min. 450 Messages during Meshing
L x W x H		100 x 100 x 60mm
Weight		Node: 0.4kg Displacement Sensor (1.0m cable) + NTC temperature Sensor with strong magnet fixing (1.0m cable): 0.25kg
Cable Gland		Qty. 1 x EMC-CMA12 – Extend Power Qty. 1 x EMC-CMA16 – Displacement and Temperature Sensor
Wire Connection		Spring type wiring terminal
WSN
Mesh Wireless Interface		WISENMESHNET® Protocol
External Primary Sensor
Sensor Type		External Displacement		External NTC Temperature
Range		0 to 50/100/150/200mm Overload cause irreversible damage		-40 to 85°C
Accuracy		0.1%FS		<1°C@[-40, 40]°C & <2°C@(40, 85]°C
Resolution		0.0015%FS		0.1°C
Standard System Parameter
Internal Temperature		Range: -40 to 85°C; Accuracy: ±1°C, typical: ±0.5°C; Resolution: 0.1°C
Voltage		Accuracy: ±0.1V
Industrial Standard
Casing and Painting Materials		Aluminium-Alloy Die Castings 12 (Epoxy Polyester Powder Coating)
IP Rating		≥ IP66
Operating Temperature		-40 to 85°C
Fire Proof		Approved
Certificates		–
Re-Calibration Method
Inspection Period		Every 3 Years by Manufacturer (or inspected by arranged methods)
Applications
The unit is combined with: A. External displacement sensor, for railway track vertical movement or crack development; B. External temperature sensor, for railway track variation monitoring. A vibration threshold trigger value can be set on a node switch, so that once the vibration threshold is reached by any object, such as a train passes by, a node can sample at 33Hz rate, and report to a gateway of maximum, minimum, average over a time interval.
Vibration Trigger Settings
Monitoring Mode	Hardware Switch Setting		Trigger Threshold