G130 Gauge – Deflection and wall tilting

Technical specifications

G130 Gauge — monitoring deflection, tilting and deformation

The G130 is a simple, accurate and rugged solution for measuring the evolution of a deflection, the tilting of a retaining wall or the deformation of a wall under compression. Built around the G3 gauge and a metrological Invar cable, it delivers reliable readings, indoors as well as outdoors.

• Accurate to 1/10^th of a millimetre
• Adaptable installation: quick bonding or mechanical fixing
• Readings taken under constant tension controlled by a calibrated spring
• Resistant to weather and UV
• Digital monitoring: saugnac.app

The G130 is built around the G3 gauge to provide reliable deformation monitoring. Its principle:

• A G3 gauge fixed to the structure being monitored
• A metrological Invar cable tensioned between two fixed points (Ø 1.65 mm, thermal expansion coefficient 4.4 × 10⁻⁷/°C between 20°C and 100°C)
• A mechanical tensioning device matched to the length of the cable

The probe of the gauge rests against the tensioned cable, and readings are taken under constant tension thanks to a calibrated spring.

Example of a drawing for monitoring the deflection of a 7.20 m beam, showing the mounting system and the calibrated spring (in red).

The system can be used in the following 3 configurations:

Monitoring the tilting of a retaining wall	Monitoring the vertical deflection of a wall under compression	Monitoring the deflection of a horizontal beam

Mounting the G130 gauge

Each installation is prepared to measure, according to the anchor points, the material and the cable length.
Custom instructions are supplied, with drawings and tension recommendations.

Example of custom instructions

Example of a custom bracket mounting for monitoring the tilting of a retaining wall

Example of a mounting for monitoring the deflection of a beam

Two mounting methods are possible for the G3 gauge:

• By bonding: fixing is quick and simple thanks to the double-sided self-adhesive pads supplied.
  For the bond to be effective, the substrate must be smooth and clean. If necessary, and in particular if the surface is not completely flat and has irregularities, the bond can be reinforced with a fast-curing two-component epoxy adhesive. In this case, it is also possible to apply the epoxy adhesive directly to the gauge without using the self-adhesive pad.
• By mechanical fixing: where the substrate is very uneven, or is crumbling with a risk of the gauge coming loose, we recommend using an intermediate plate. This plate is fixed mechanically to the substrate with impact anchors (supplied with the plate), and the gauge is then bonded to the plate. The plate becomes the mounting surface.

Reading the G130 gauge

Readings are taken using a vernier scale to 1/10 mm. Note the letter of the face being read, A or B, so that readings are always compared against the same face over time.

The difference must be multiplied by 2 to obtain the evolution of the deflection to a tenth of a millimetre.

For a fuller explanation of how this works, refer to the G3 gauge instructions.

Recording kit

We offer an add-on recording kit that mounts on the G3 gauge. This kit records the maximum and minimum deformations of the structure graphically.

More information on the G3 recording kit product page.

Digital monitoring with the app

Readings are recorded directly in the saugnac.app application, using the unique identifier printed on the gauge. Access to the app is free, on both PC and smartphone.

For a study and a tailored quotation: contact us.