Alignment Sensors

4B's line of sensors and switches are designed to detect (mis)alignment and motion on bucket elevators & belt conveyors.

4B's WDA sensor can also be used as a slack chain detector on drag chain conveyors.

View our Full Electronics Catalogue here.

Updated Version
4b Touchswitch sensor


  • Force Activated Belt and Pulley Alignment Sensor
  • Instantaneous Misalignment Indication
  • Hardened Stainless Steel Contact Face
  • External Test Feature
  • Output LED Indication
  • Not a Rub Block
Bulldog - Conveyor Belt Misalignment & Rip Detection System


  • Conveyor Belt Misalignment & Rip Detection System
  • Electro-mechanical system designed to detect dangerous misalignment of the conveyor and also detection of belt tear damage
  • Triggers an alarm at 20º and a shutdown of the machine at 35º
  • Easy installation
  • Robust design
  • No calibration required
  • Nylon rollers as standard; stainless steel rollers available on request
WDA sensor - belt speed / alignment / chain break sensor
  • Magnetic Proximity Belt Speed and Belt Alignment Sensor
  • Detects Moving Steel Ferrous Targets
  • Adjustable Sensing Range of 25 – 75mm
  • Not Affected by Material Build Up
  • Stainless Steel Construction
  • High Temperature Version Available
BAP belt alignment sensor for bucket elevators

BAP Misalignment Sensor

  • Rugged housing for the most arduous environments
  • Fail safe magnetic sensor immune to build up of material
  • Powerful sensing range of 12 – 50mm, easily adjusted on the sensor or at the control unit
  • Links direct to PLC or to independent control unit A400 Elite or Watchdog Elite