G2 Gauge

Detailed description of G2 gauge

The purpose of the G2 type gauge is to measure and record the changes in the gap of an expansion joint, the gap between the edges of a gap and/or, more generally, the change in distance between 2 elements.
The change measured is recorded by a trace on a graduated scale.

This G2 Saugnac Gauge is based on the same two concepts:

• Measurements are made using a vernier measuring to 1/10th of a mm.
• They can be fixed in place using double-sided self-adhesive tabs. We recommend however mechanical attachment with plugs and screws supplied with the gauge.

The G2 is a maximum minimum gauge. It mainly comprises a plate and a sliding tongue, each being attached on one side of the gap. Like the G1 gauge, the tongue has marked divisions and moves in front of a vernier scale set at 1/10th of a mm. When the tongue moves it also moves an arm which has a lead at its end, held pressed down by a small strip of polycarbonate. The trace made by the lead shows movement on a scale X 3. A table is provided for noting the date, the vernier readings and the temperature in °C. A removable casing, ventilated to avoid condensation, protects the device. The casing can be security sealed; a lead seal is supplied with the gauge to secure the device.

Technical characteristics

• Reading the crack evolution to 1/10th of a mm using a vernier
• Supplied with casing
• Dimensions 120 X 250 mm,  depth 27 mm with the casing
• Weight: 125g
• Traction force in the order of 150/200 g

A record of the maximum/minimum variation in the gap is traced by a N°7B lead onto a white graduated scale.
After observation, the mark can be erased with alcohol and the gauge re-used.

The G2 gauge avoids visits for monitoring changes, especially helpful when the gauges are difficult to reach.

Fixing the G2 gauge

As a general rule, adhesive tabs are sufficient. If the structure does not have a very satisfactory surface, spread a thin layer of glue or attach by mechanical means: three 2.5 mm holes are provided for this purpose.
Drill to 4 mm for fixing with plugs and screws

On damaged surfaces with distortion in many directions, we advise fixing the arm of the gauge with a ball joint (please enquire)..

Examples of fixing with angle bar

To measure and record the change in a gap or joint in an internal angle, we suggest using an angle bar. We can supply self-adhesive aluminium angle bars on request. (30 X 20 X 3 mm)

One wing of the angle bar is attached to one part of the structure. The other wing has the arm of the gauge attached to it, the latter being attached to the other part of the structure under observation.