Vibrating Wire Sensor Node

The FlatMesh Vibrating Wire Sensor Node brings a wide variety of vibrating wire sensors into the FlatMesh system. It is a highly integrated system which is capable of exciting and sampling vibrating wire sensors and reporting its measurements through Senceive’s FlatMesh wireless communications network to a FlatMesh Gateway.

Examples of the sensors supported:

  • Piezometers
  • Strain Gauges
  • Crack Metres
  • Load Cells
  • Pressure Cells

Key benefits

  • High performance, easy to connect multichannel connectors
  • Waterproof, robust connectors for simple installation
  • Resolution of 0.001 Hz and repeatability of ±0.02 Hz
  • Integrated long life battery
  • 12-15 years’ battery life, including when acting as a relay node within the mesh communications network
  • Integrated temperature sensor
  • Versatile mounting options
  • Waterproof to IP66 / IP67 / IP68
  • Firmware is remotely upgradeable over the air via the gateway reducing costly site visits

Channel Combinations

Model Ports Applications
FM3N-VW11 1 VW and 1 Thermistor Channel Single sensor
FM3N-VW41 A: 1 VW and 1 Thermistor Channel

B: 1 VW and 1 Thermistor Channel

C: 1 VW and 1 Thermistor Channel

D: 1 VW and 1 Thermistor Channel

Four strain gauges in an array

2+ sensors in close proximity

FM3N-VW17 7 VW and 1 Thermistor Channel Single load cell

Physical Specifications

Parameter FM3N-VW11 / VW17 FM3N-VW41
Dimensions excluding antenna and vent 90 x 90 x 60 mm 90 x 130 x 50 mm
Dimensions excluding antenna 90 x 96 x 60 mm 90 x 136 x 50 mm
Total Mass 0.57 kg 0.75 kg
Housing Material Die cast aluminium Die cast aluminium
Protection
(BS EN 60529: 1992 + A2: 2013)
IP66 / IP67
IP68 at 1m for 24 hours
IP66 / IP67
IP68 at 1m for 24 hours
Mounting Options Clearance holes for M4 socket head screw in bottom M4 blind holes in side Clearance holes for M4 socket head screw in bottom
Operating Temperature Range -40°C to +85°C

FlatMesh Radio Specifications

Parameter Value
* Consult with Senceive for your application
Communication Type Proprietary FlatMesh v3 Mesh Networking Protocols IEEE 802.15.4 compliant
Frequency Band 2400 – 2485 MHz ISM Band
Maximum Transmit Power (EN 300 328 v1.8.1) 6.5dBm
Maximum Permitted Antenna Gain 2.2dBi
Range Up to 300m depending on the environment and fitted antenna *

Vibrating Wire Interface

Parameter FM3N-VW11 / VW17 FM3N-VW41
Connector M12 Female
5-pole A-coded
Screw-in Type
M12 Female
12-pole A-coded
Screw-in Type
Frequency Resolution 0.001 Hz
Frequency Repeatability ±0.02 Hz
Frequency Range 200-6500Hz
Stimulus Type Swept Sine Wave, typ. 6V peak to peak
Thermistor Type 3kΩ NTC
Temperature Resolution 0.05
Temperature Accuracy ±0.1°C
Temperature Range -40°C to +85°C

Internal Battery

Parameter FM3N-VW11 / VW17 FM3N-VW41
*consult with Senceive for your application
Battery Type Lithium Thionyl Chloride
Nominal Voltage 3.6V
Nominal Capacity 19000mAh 34400mAh
Typical Battery Life 12-15 years at 20/30 minute reporting intervals, including when acting as a relay node*

Certifications

  • Tested to conformity with all the essential requirements of R&TTE Directive 1999/5/EC and RoHS Directive 2011/65/EU
  • Network Rail Acceptance PA05/04146
  • London Underground Approved Product ID 2073

Ordering Information and Accessories

Model Description
FM3N-VW11 FlatMesh 3 Vibrating Wire Sensor Node (1x 1-wire port)
FM3N-VW41 FlatMesh 3 Vibrating Wire Sensor Node (4x 1-wire port)
FM3N-VW17 FlatMesh 3 Vibrating Wire Sensor Node (1x 7-wire port)
FS-VWCON11 Sensor Connector for 1-wire sensor

Screw terminals for easy installation

Sensor cable outside diameter 5.0-8.0 mm

Suits FM3N-VW11 or FM3N-VW41

FS-VWTRM17 Terminal Block and Cable for multi-wire sensor
Screw terminals for easy installation
Suits FM3N-VW17
FT-VW-TH11 Test Harness for 1-wire sensors

Mates to FS-VWCON11 for easy connection to hand-held vibrating wire readout device (not supplied)

FT-VW-TH17 Test Harness for multi-wire sensors
Mates to FS-VWTRM17 for easy connection to hand-held vibrating wire readout device (not supplied)
FA-FM-WPS Waterproof straight antenna

Overall node height

– 168mm (approx) when fitted to FM3N-VW11 or FM3N-VW17

– 158mm (approx) when fitted to FM3N-VW41

Maximum gain +1.1dBi

FA-FM-LPS Waterproof low profile straight antenna
Minimum overall node height, perfect for track bed and tight spots
Overall node height;

  • 92mm (approx) when fitted
    Maximum gain 0dBi when fitted to FM3N-VW11 or FM3N-VW17
  • 82mm (approx) when fitted to FM3N-VW41
    Maximum gain 0dBi
FA-FM-ADJ Adjustable angle antenna

Flexible installation, perfect for use in tunnels and indoor environments

Overall node height when upright;

  • 202mm (approx) when fitted to FM3N-VW11 or FM3N-VW17
  • 192mm (approx) when fitted to FM3N-VW41

Overall node height when at 90-degree angle;

  • 102mm (approx) when fitted to FM3N-VW11 or FM3N-VW17
  • 92mm (approx) when fitted to FM3N-VW41

Maximum gain +2dBi

FC-NC Antenna cover kit
Fits FM3N-VW11 and FM3N-VW17 only
Use with FA-FM-LPS antenna
Overall node height 96mm (approx) when fitted