Tape Extensometer

Applications

The tape extensometer is used to detect and monitor changes in the distance between two reference points. Typical applications include:

• Monitoring convergence of tunnel walls.
• Monitoring deformations in underground openings.
• Monitoring displacement of retaining structures, bridge supports, and other structures.

Operation

Stainless steel reference points are permanently installed at measurement stations along the tunnel or structure.

To obtain a measurement, the operator stretches the tape between two reference points, hooking the free end of the tape to one point and the instrument body to the other.

The operator tensions the tape by turning a knurled collar until two index marks are aligned and then notes the reading from the tape, the internal sliding scale, and the dial gauge. The sum of these readings is the distance between the two reference points.

By comparing the current reading to the initial reading, the operator can calculate the change in distance between the two reference points.

Advantages

Repeatable Measurements: The tape extensometer provides repeatable measurements over spans up to 20 meters or 66 feet.

Economical Reference Points: Stainless steel eyebolt reference points are economical and easy to keep clean. The eyebolts can be bolted or welded to the structure or threaded into groutable or expansion-type anchors.

Rugged: Precision parts are protected by a strong aluminum body and a plastic lens.

Easy to Use: The tape extensometer's hook and eyebolt system is easy to use and offers unrestricted angular movement of the tape. Tape tension is easy to adjust, even when the operator wears gloves.

For more information

Please visit the Slope Indicator website to download a data sheet and a manual. These documents can be viewed and printed with Adobe Acrobat Reader.