R2 Gauge – Wireless crackmeter with large-range external sensor

Technical specifications

R2 Gauge – Wireless crackmeter with large-range external sensor

The R2 gauge is a wireless crackmeter designed to measure large crack movements, up to 100 mm.
Thanks to its linear sensor, external to the housing and connected by a cable (approx. 1 m), it is ideally suited to structures where crack opening variations can be significant—applications where the R1 gauge (23 mm range) reaches its limits.

The R2 gauge builds on the proven principles of the Saugnac remote monitoring sensors range, while extending the field of application to contexts involving greater structural deformation.

Continuous remote monitoring removes the need for repeated technician site visits: measurements are taken automatically and pushed to the app, where they can be reviewed at any time from a computer or smartphone.

The R2 gauge is supplied pre-calibrated and ready to use. A calibration certificate in accordance with standard FD X07-012 is available as an option.

✔️Key points

• Cabled external linear sensor – 100 mm range
  Ideal for wide cracks or significant movements on concrete, masonry, etc.
• Integrated humidity and temperature sensors to correlate changes with ambient conditions.
• Web and mobile application with unrestricted access, to view data remotely and in real time.
• One-year subscription included (activated upon first commissioning).
  Data remain available in the app even after the subscription expires.
• No data loss without network: if coverage is temporarily unavailable, measurements continue to be recorded and are transmitted automatically once the network is restored.
• Mounting hardware supplied for solid or hollow substrates.
• Reusable gauge after data archiving.
• Multi-operator connectivity ensuring reliable communication via the best available local network.
• Battery life up to 8 years, depending on measurement and transmission frequency.
• Remote configuration via the app to adjust parameters to monitoring needs.

🌐Remote crack monitoring with the app

All information from the three sensors—displacement, temperature and humidity—can be viewed via the app https://saugnac.app on both smartphone and computer.
Access to this app is completely free, as for all our measuring instruments. Even after the data transmission subscription expires, your account and measurement history remain available.

The interface makes it possible to display customizable graphs, downloadable as image files for easy integration into your reports.
Raw data can also be exported to Excel or CSV files for additional analysis.

A shareable link can be generated to provide access to a dynamic report, always up to date at the time it is viewed.

Finally, the app includes a system of configurable alerts: you can set a threshold up or down relative to the first measurement. If exceeded, an email notification is automatically sent.

🚨“Monitoring+” mode: enhanced monitoring activated remotely

During exceptional events (works, impacts, unusual movements, structural alert), the R2 gauge can be switched to “Monitoring+” mode, activated remotely.
This mode increases the measurement and transmission frequency for closer, more responsive monitoring.

The configurable parameters are:

• Measurement frequency: every 2, 5, 10, 20 or 30 minutes
• Transmission frequency: every 1, 2, 3 or 4 hours

Once the maximum duration is reached, standard mode automatically resumes to preserve battery life and data volume.
“Monitoring+” can be reactivated several times for specific monitoring campaigns, up to 12,000 measurements.

Applications of the R2 wireless crackmeter

With its 100 mm measurement range and external cabled sensor, the R2 gauge is suited to structures where crack openings or movements can reach several centimetres:

• Bridges, viaducts and civil engineering structures
• Tunnels and underground works (only if there is network coverage inside the tunnel)
• Retaining walls, dams and hydraulic structures (housing rated IP66, sensor IP65: resistant to splashing and bad weather, but not submersible)
• Historic monuments and heritage buildings
• Any masonry or concrete structure with wide or fast-moving cracks

Its integrated temperature and humidity sensors provide a complete picture of the environmental conditions affecting the structure, supporting a more reliable structural diagnosis.

Quick installation and commissioning of the R2 gauge

The R2 gauge has been designed for a simple, intuitive installation, achievable without any specific technical knowledge.

With the supplied mounting hardware and the Saugnac app (accessible on smartphone or computer), commissioning takes only a few minutes.
An illustrated manual is supplied with each device to guide the user step by step.

1. Registering the gauge in the app

Open the Saugnac app and add your R2 gauge by scanning the QR code on the housing or by manually entering the identifier printed underneath. The gauge then appears in your interface, ready to be configured.

2. Measurement settings

From the app, customize the settings according to your monitoring needs:

• Time of the first measurement
• Measurement frequency: every 1h, 2h, 4h, 6h, 8h, 12h or 24h
• Data transmission frequency: every 12h, or every 1, 2, 3 or 7 days

💡 The more spaced out the transmissions, the longer the crackmeter battery life.

3. Powering on

Carefully open the housing and switch on the internal toggle.
The gauge automatically connects to the network and indicates correct operation via an LED indicator.
Once initialized, it goes into standby until the first scheduled measurement.

4. Mounting on the structure to be monitored

Position the linear sensor and mount the R2 gauge using the supplied components:

• Solid substrate (concrete, stone): use the brass anchors
• Hollow substrate (brick, cinder block, light partition): use the EPDM anchors

Mounting the wireless crackmeter

The R2 gauge is supplied with 2 types of anchors:

Brass anchors for solid substrates requiring Ø8 mm holes.
Required tools not supplied for mounting on solid substrates with brass anchors: drill, Ø8 mm drill bit, 5 mm hex key + 3 mm hex key to open the housing and power on the R2 gauge.

EPDM anchors with nuts and washers for hollow substrates (also usable on solid substrates) requiring Ø13 mm holes.
Required tools not supplied for mounting on hollow (or solid) substrates with EPDM anchors: drill, Ø13 mm drill bit, 5 mm hex key + 3 mm hex key to open the housing and power on the R2 gauge.

To mount the gauge, first mount the housing, then the sensor. Mounting is done easily using the supplied hardware. All operations are described step by step in the detailed manual.

📐Angled mounting or shear displacement monitoring

With the R2 mounting kit (sold separately), angled mounting or shear displacement monitoring is possible.

Subscription and network coverage

The subscription included with the R2 crackmeter is valid for one year.
After expiry, access to previously recorded data remains available, but new measurements are no longer transmitted until the subscription is renewed. Email notifications are automatically sent before the expiry date to inform the user.

Renewal can be completed directly from the app, either via secure credit card payment or via a purchase order generated from an automatic quotation. The annual subscription fee is €49 excl. VAT.

Frequently asked questions

What is the difference between the R1 gauge and the R2 gauge?

Both gauges work on the same remote monitoring principle and use the same app. Three things set the R2 apart:

• the range: the R1 is compact and covers 23 mm, while the R2 has an external linear sensor covering approximately 100 mm
• the 1 m cable between the sensor and the housing, which allows the housing to be positioned away from the crack and gives greater freedom of installation
• a larger antenna inside the housing, which improves network reception in difficult configurations

Can the R2 monitor a shear movement?

Yes, with the R2 mounting kit, which allows angled installation or the monitoring of a shear movement.

Can the gauge be installed outdoors?

Yes. The housing is IP66 and the sensor IP65, for an operating range from −30°C to +70°C.

Does the gauge work in a basement or a car park?

The multi-operator LTE-M / NB-IoT communication module is designed for industrial connected devices and offers good signal penetration. Transmission remains possible in cellars, basements or car parks, depending on the site configuration. Thanks to its larger antenna, the R2 performs better than the R1 in borderline cases.

What is “Monitoring+” mode for?

It temporarily tightens monitoring during a specific event (works, impact, unusual movement), with up to one measurement every 2 minutes. It is activated remotely from the app, with no site visit, and standard mode resumes automatically at the end of the period.

How do the alerts work?

A threshold is set in the app, up or down, relative to the first measurement. Each time this threshold is exceeded, a notification is sent by email.

Is there a charge for the app?

No. It is supplied with all our instruments, with no time limit and independently of the subscription, which only covers data transmission.

What tools are needed for the installation?

The fixings are supplied for solid substrates (brass anchors, Ø8 mm holes) and hollow substrates (EPDM anchors, Ø13 mm holes). You will need to provide a drill, the matching drill bit and two hex keys (5 mm and 3 mm) to open the housing.

Can the battery be replaced?

Yes. Battery life is between 2 and 8 years depending on the settings, and an end-of-life alert is sent so that replacement can be anticipated. The battery is easy to change by following the manual.

Is the gauge reusable?

Yes, on another site once the data from the previous monitoring campaign has been archived.