R20 gauge – Wireless extensometer

Technical specifications

Overview of the R20 wireless extensometer

The R20 gauge is a wireless electronic extensometer specifically designed for remote monitoring of the displacement / convergence between two points several metres apart, with a resolution of 0.01 mm.

What is a wireless extensometer used for?

The wireless extensometer builds on the physical principles of the mechanical extensometer (also known as a convergence meter) while adding the benefits of a connected sensor: all readings are taken automatically.

In addition to the linear displacement sensor, an ambient temperature sensor and a relative humidity sensor enable a complete diagnostic and help identify any potential correlation with climatic conditions.

R20 wireless extensometer: operating principle and advantages

Based on the R1 wireless crack monitor, this connected extensometer gauge shares its main technical and functional features:

• Three integrated sensors: linear displacement, ambient temperature and relative humidity.
• Intuitive configuration in a few clicks, with no IT expertise required.
• Extensive connectivity covering all European countries.
• Long battery life: up to 7 years (depending on data transmission settings).
• Flexible configuration, adjustable remotely.
• Dedicated app accessible from a smartphone or web browser.

A one-year subscription is included with the R20 gauge, starting from first initialisation. It can be renewed directly via the app or by purchase order. For further information on how the R1 gauge works, please refer to the R1 gauge product page.

The Invar cable, with its very low thermal expansion coefficient, is cut to length according to the installation context and can be adjusted by ±15 cm on site.

Thanks to data transmission via the app, the R20 gauge can be installed at height, out of reach, or at a more accessible level to facilitate maintenance if required.

Examples of R20 gauge installation on pillars in a church by the company EGSOL

Remote monitoring of the displacement between 2 points

The R20 wireless extensometer uses the same operating principles as the G20 gauge to measure the change in distance between two points, A and B, separated by a distance D (in metres).

Point (A) is a ring with a fixing bracket.

Point (B) is a ball-bearing fixed to a bracket that redirects the Invar wire vertically down to the monitoring station.

An Invar cable (1) is fixed on one side to point (A) and on the other side to the counterweight of the station (2). Between its two ends, the Invar wire runs over the ball-bearing