EL Beam Sensor


The DGSI EL Beam Sensor is used to monitor differential movement and rotation in structures. Typical applications of the EL Beam Sensor include:

  • Monitoring stabilization measures, such as pressure grouting and underpinning.
  • Monitoring structures which may be affected by nearby tunneling and excavating.
  • Evaluating the performance of bridges and beams under load.
  • Monitoring the stability of structures in landslide areas.
  • Monitoring the deflection and deformation of retaining walls.
  • Monitoring convergence and other movements in tunnels.
EL Beam Sensor : Horizontal and Vertical Tiltmeters


The EL Beam Sensor consists of an electrolytic tilt sensor attached to a rigid metal beam. The tilt sensor is a precision bubble-level that is sensed electrically as a resistance bridge. The bridge circuit outputs a voltage proportional to the tilt of the sensor. The beam, which is typically one to two meters long, is mounted on anchor bolts that are set into the structure. Movement of the structure changes the tilt of the beam and the output of the sensor

schematic diagram of el beam sensor in use

The voltage reading from the EL Beam Sensor is converted to a tilt reading in mm per meter. Displacements are then calculated by subtracting the initial tilt reading from the current tilt reading and multiplying by the gauge length of the sensor (the distance between anchors). When sensors are linked end to end, displacement values can be accumulated from anchor to anchor to provide a profile of differential movements or settlements.

Because the EL Beam Sensor has a very narrow range, it is necessary to "null" the sensor at installation time. This provides the maximum measurement range and also takes advantage of the sensor's best characteristics.
The EL Nulling Device or the EL Data Recorder are convenient tools for the nulling operation.


For more information

Please download the EL Beam Sensor datasheet and manual. These documents can be viewed and printed with Adobe Acrobat Reader.

EL Beam Sensor & Tiltmeters Specifications

EL Tilt Sensor, Standard56802100
EL Tilt Sensor, SC56802120
SensorUniaxial electrolytic tilt sensor housed in a weatherproof aluminum enclosure with terminals and cable gland for signal cable. Does not include bracket, beam, or anchors. The standard version of the tilt sensor works with Campbell Scientific CR1000, CR800, and CR10X data loggers. The SC version of the tilt sensor includes a signal conditioning board and a temperature sensor. It works with Campbell Scientific data loggers, the M-Logger, and readouts such as the EL/MEMS data recorder.
Range±40 arc minutes
Resolution1 arc second using a Campbell Scientific CR1000 data logger
Repeatability± 3 arc seconds
Adjustment RangeThe sensors provides an adjustment range of ±4° to ease installation
Operating Temperature–20 to +50°C.
Dimensions125 x 80 x 59 mm deep (4.9 x 3.2 x 2.3")
Signal Cable for Standard Sensor50612804Shielded cable with four 24-gauge tinned-copper conductors and PVC jacket.
Signal Cable for SC Sensor50613527Shielded cable with seven 22-gauge tinned copper conductors and polyurethane jacket.
Order a tilt sensor, a bracket, a beam, and anchors to secure the beam to the structure.
Omni Bracket56801355KThe Omni-bracket holds the tilt sensor onto horizontal, vertical, or inclined beams. Self-tapping screws are included to fasten the bracket to the beam.
1 meter Beam56801612
2 meter Beam56801614
3 meter Beam56801616
3 foot Beam56801623
6 foot Beam56801626
10 foot Beam56801630
Spare End-Bracket5680181538 x 38 mm square-section aluminum beam includes two end-brackets. Beams are sized to provide a gauge length that is measured from anchor to anchor. Anchors are not included
Groutable Anchors56801910KGroutable anchor for beam Includes one allthread stud, low-friction bushings, and other hardware. For stand-alone beam sensors, order two anchors. For linked beams that share an anchor, order one anchor for each beam plus one additional anchor for the last beam.
Order a tilt sensor, a bracket, and an anchor for each sensor.
Rotating L-Bracket56801350KThe L-bracket holds the tilt sensor perpendicular to the structure. The bracket rotates nearly 360 degrees, so it can be mounted on inclined structures, floors, and ceilings, as well.
Omni Bracket56801355KThe Omni-bracket holds the tilt sensor parallel with the structure.
Expansion Anchor57803128The expansion anchor is installed in a 9.5 x 64 mm (3/8 x 2.5 in) drill hole and includes a bolt and washer to hold the L-bracket.
Groutable Anchor57803130KThe groutable anchor is installed in a 13 x 90 mm (0.5 x 3.5 in) drill hole and includes a bolt and washer to hold the L-bracket. Requires epoxy grout available locally or ordered below.
Epoxy Grout Kit57803133Includes plastic dispenser and cartridge of quickset epoxy grout. Sufficient for 15 anchors.
Campbell Scientific Data LoggersThe CR1000 Logger can monitor 12 standard or 3 SC sensors directly. Up to 32 standard sensors or 16 SC sensors can be connected to an AM16/32 multiplexer. See separate datasheet.
M-LoggerThe M-Logger can monitor one SC sensor directly or 16 SC sensors connected to an AM16/32 multiplexer. See separate datasheet.
EL / MEMS Data Recorder56813500This portable readout displays and records readings from SC sensors. Tilt readings are displayed in volts; temperature readings in degrees C. It can also be used for nulling the sensors. See separate datasheet.
EL Nulling Device56803300The EL Nulling device provides a convenient way to zero sensors at installation time. The nulling device is compatible with both standard and SC tilt sensors.