G3 Gauge – Misalignment and offset

Technical specifications

Overview of the G3 gauge for monitoring misalignment / offset

The G3 gauge is designed to measure the evolution of a vertical misalignment (rocking floor slabs) or horizontal misalignment or, more generally, the evolution of out-of-plane movement, perpendicular to an X,Y reference plane.

It consists of a 50 mm cubic body, an arm integral with the body, and a 70 mm stainless steel rod that fits into the arm and rests against the structure to be monitored. The engaged length of the rod is adjusted according to the size of the misalignment to be measured.

Monitoring the evolution of a horizontal misalignment (structures lying in a horizontal plane): floor slab failure or ceiling sagging (A = structure whose movement is to be measured, B = fixed reference structure, d = misalignment)

Monitoring the evolution of a vertical misalignment (structures lying in a vertical plane): pillar out of alignment or sliding structure (A = structure whose movement is to be measured, B = fixed reference structure, d = misalignment)

The measurement is taken using a vernier reading to 0.1 mm, corresponding to 0.2 mm of movement.

A = B: Plane Z
C: Plane XY
D: Misalignment
(1) double-sided self-adhesive tab 50 x 50 mm
(2) stainless steel rod ø 4 mm, length 70 mm

How to fix the G3 gauge?

Its cube shape allows it to be used in any position: along a skirting board, or in a vertical or horizontal internal corner, by choosing one of its 5 faces to fix the gauge (see below for installation examples).

Two fixing methods are possible:

• By bonding: fixing is quick and easy with the double-sided self-adhesive tabs supplied. The self-adhesive tab is applied to one of the 5 available faces of the cube, so the fixing can be adapted to the location and the measurement to be taken. Two tabs are supplied, so that the gauge can be reused or a bonding error corrected.
  For the bond to be effective, the surface must be smooth and clean. If necessary, particularly if the surface is not perfectly flat and has rough spots, the bond can be reinforced with a fast-curing epoxy glue in a twin syringe. In this case, the epoxy glue can also be applied directly to the gauge without the double-sided adhesive tab.
• By mechanical fixing: where the surface is very uneven, or crumbles with a risk of the gauge coming loose, we recommend using an intermediate plate. This plate is mechanically fixed to the surface with impact anchors (supplied with the plate), and the gauge is bonded to the plate, which then becomes the mounting surface.

A: 2 x 4/40 screws, B: Intermediate plate, C: Self-adhesive tab, D: Expansion joint

The rod length is adjusted according to the size of the misalignment: an offset of up to approximately 50 mm is possible; beyond that, a special assembly is required. Please contact us if needed.

Installation examples:

G3 gauge installed on a ceiling with the supplied self-adhesive tabs

G3 gauge installed with an intermediate plate on an uneven, damp surface

G3 gauge fixed on its side to measure ground settlement

G3 gauges fixed to measure the misalignment of a pillar relative to its capital following an earthquake

Adjusting the rod length according to the misalignment

Special assembly for a large misalignment

How to protect the G3 gauge?

We offer protection with a thermoformed plastic cover or an IP65 aluminium cover.

1- Protection with a plastic cover
A semi-flexible, transparent cover measuring 27 x 13 x 9 cm protects the gauge from the weather, dust and vandalism. The cover is fixed to the surface with a self-adhesive strip and impact anchors.

G3 gauge installed outdoors with the transparent cover

Fixing detail with impact anchors

Reading through the transparent cover

2- Protection with an aluminium cover
For “high protection”, we offer aluminium enclosures measuring 175 x 80 x 57 mm (depth).

How to read the G3 gauge?

The reading is taken using the vernier principle, to 0.1 mm. Note the letter of the face read (A or B) so that measurements are always compared on the same face over time.

a) Reading the millimetres:

The millimetre graduation located to the left of the ꓕ gives the measurement as a whole number of mm. In the example, the reading is therefore: 12 mm.

b) Reading the decimal:

Find the vernier line that coincides with a line on the measuring scale.

This vernier line gives the tenth of a millimetre. In the example, the reading is therefore: 0.4 mm

The measurement is therefore 12.4 mm

Due to the design of the gauge, for geometric reasons, the change in misalignment is equal to twice the difference between the 2 measurements.
∆h in mm = (M2 – M1) x 2
Example:
– Measurement 1 = 21.3 mm taken on 12 January 2022
– Measurement 2 = 21.6 mm taken on 24 April 2022
– Change in misalignment = (21.6 – 21.3) x 2 = 0.3 x 2 = 0.6 mm

Recording kit

We offer an add-on recording kit to be mounted on the G3 gauge. This kit graphically records the maximum and minimum deformation of the structure.

More information on the G3 recording kit product page.

Download the Saugnac.app application to monitor your G3 gauge measurements

The Saugnac web app, completely free with no limitations, is available on PC or smartphone at https://saugnac.app. Each G3 gauge has a unique QR code and ID to link the measurements to the gauge. The application allows you to:

– identify each gauge and its measurements with the unique QR code on the G3 gauge
– record the measurements in your account
– calculate the change in misalignment
– retrieve the temperature and humidity via geolocation
– collaborate with several people on the same gauge
– manage alert thresholds
– sort the gauges by location and locate them on a map
– download the data in Excel format
– display graphs automatically
– share the data with people who have no account
– access the application from your PC or smartphone
– add measurements without a connection in offline mode

Find all the explanations on how the application works