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Fail-Safe Void Detection Sensor

Rail Ballast, Embankments, Bridge Scour, Landslides, Structural Separation

Picton BIS sensor
Picton BIS sensor logo

Instant notifications of integrity loss

No calibration required

>25 year 
operational life

Prevented major incidents and saved lives


Precision Engineering

The BIS sensor is manufactured to the highest precision engineering standards to ensure total confidence in the device's operation. 


How it works

Good / No Good Status 

The BIS comprises of an on/off switch that activates when the nose cone becomes disconnected from the sensor body.

Adjustable Threshold

Adjustable trigger threshold from 1.5" to 3.5" (38.1mm to 88.9mm)

Durable, High Quality Materials

The BIS housing is constructed of aluminium to ensure low corrosion over the lifetime of the installation.

Instant Notification of Activiation

Output signal can be connected to multiple monitoring systems or directly to signalling systems




  • What power supply is required for the BIS
    As the BIS operates as an on/off, good/no good switch the BIS has no power consumption during operation. The maximum power rating for the device is 30Vdc / 125Vac
  • How is the BIS activated by a void?
    The BIS consists of a main sensor body and a nose cone. The sensor body is affixed to a static reference point (rail sleeper, bridge structure...) by means of high strength cables or bolts. When the nose cone is no longer supported by the surrounding strata the nose cone will separate from the sensor body. Based on the threshold set, once exceeded, the sensors switch will trigger.
  • Does the BIS provide movement measurements?
    No. The BIS is intended to provide a fail safe alert of lost integrity. When activated the BIS has identified a total loss of the nose cones support and as such the relating structure is no longer supported.
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