G1+ Gauge

Technical specifications

How to fix the G1+ crack monitor

For the most accurate monitoring, attach the crack monitor at the widest point of the crack, typically in the middle. The G1+ gauge is made of flexible material that adapts to irregular, convex, or concave surfaces.

Two fixing methods are possible:

• Gluing: Attach using the supplied double-sided adhesive pads. Ensure the surface is clean, dry, smooth, and stable. For rough or uneven surfaces, bonding can be reinforced with a fast-curing epoxy adhesive.
• Mechanical fixing: The G1+ gauge has two Ø 4 mm holes for easy mounting with plugs and screws. For fragile or uneven surfaces, mechanical mounting is recommended to prevent detachment. 50-plug and screw sets or a complete mechanical mounting kit (includes drill, screwdriver, plugs, and screws) are available.

Installation tips

Position the crack monitor where the crack is widest. It can be placed across vertical, horizontal, or oblique cracks. The flexible G1+ gauge follows the surface movement accurately.

Ideally, position the vernier triangle between 33 and 34 so that the speckled bands appear on both sides. The first reading serves as the zero reference; measure differences over time.

Measuring cracks in corners

The latest G1+ gauges (from mid-2025) have a groove marked on the folding tab to facilitate corner mounting without extra accessories. Earlier versions include a foldable tab with a thin section to guide bending.

Example corner installations:

Protecting your G1+ gauge

UV protection is recommended for gauges in public areas. UV protection covers are available and fixed with supplied anchors.

For high-traffic zones, use the removable E1 crackmeter with transparent plates. Only the plates remain on the structure after measurement, preventing damage.

Reading the G1+ digital crack monitor

The G1+ gauge provides a digital readout in tenths of mm. Each 1/10 mm movement of the tab blocks a row of 6 white lights corresponding to digits 0–9.

Subtract the first reading from the second to determine crack growth.

Crack growth over 90 days = 0.55 mm. Use the vernier if verification is needed (instructions in G1 product sheet).

Download Saugnac.app

Free PC and smartphone application at https://saugnac.app. Features:

• Identify gauges via unique QR code
• Save measurements and track gauge evolution
• Retrieve temperature and humidity via geolocation
• Adjust measurements for thermal expansion
• Collaborate on the same gauge with multiple users
• Set alert thresholds
• Locate gauges on a map
• Export data in Excel format
• Display graphs automatically
• Share measurements without an account
• Add measurements offline

Full instructions: how the app works

Download Excel monitoring file

Use the Excel file to track up to 10 gauges per site. The file adjusts measurements for temperature-related expansion. If no temperature reading is available, leave blank.

Note: Expansion effect on G1+ readings is very small (~9 µm per 1°C).