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Bonded Strain Gauges

Waterproof 3 Axis Rosette Strain Gauge

Typical electrical cubicle including Data logger, power source and signal conditioning circuits.

Two Axis Rosette

Bondable Strain Gauges are small, single use items that are designed for measuring strain in a variety of materials without the need to be physically present at the point of measurement. Multiple positions can be measured at one time also.

Application
There is a wide variety of strain gauges manufactured to suit nearly all applications. Generally each project will require their own type of strain gauge based on the requirements.                          We however carry a large array of standard sizes for emergency projects.
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Typical applications include :
- Concrete Structures ( Bridges, Silos, Jetty's, Deck Units)
- Steel Structures ( Industrial Framework , Bridges, Tanks)
- Timber Structures ( Framework, Piles )                                                          

Quality & Accuracy:
We only use Japanese manufactured units from TML Japan.        The accuracy and repeatability of bondable strain gauges is generally very good.

Preparation:
Typically, an area of concrete, steel or timber is ground and polished to allow strain gauges to be adhered using specialty adhesives. Waterproof gauges are also available for exterior measurement.

Measurement:
Very small changes in the material under tension or compression leads to change in electrical resistance of the strain gauge
through a series of circuitry, the signal is converted into a digital DataStream that can be recorded, viewed and replayed on a site laptop or directly through the strain data logger.

Safety
As there is no need to be under or around part of the structure during measurement, normal operations can generally continue without the need for restricted operating conditions or interruption to production.Bondable Strain Gauges are small, single use items that are designed for measuring strain in a variety of materials without the need to be physically present at the point of measurement. Multiple positions can be measured at one time also.

Application
There is a wide variety of strain gauges manufactured to suit nearly all applications. Generally each project will require their own type of strain gauge based on the requirements.                          We however carry a large array of standard sizes for emergency projects.
​
Typical applications include :
- Concrete Structures ( Bridges, Silos, Jetty's, Deck Units)
- Steel Structures ( Industrial Framework , Bridges, Tanks)
- Timber Structures ( Framework, Piles )                                                          

Quality & Accuracy:
We only use Japanese manufactured units from TML Japan.        The accuracy and repeatability of bondable strain gauges is generally very good.

Preparation:
Typically, an area of concrete, steel or timber is ground and polished to allow strain gauges to be adhered using specialty adhesives. Waterproof gauges are also available for exterior measurement.

Measurement:
Very small changes in the material under tension or compression leads to change in electrical resistance of the strain gauge
through a series of circuitry, the signal is converted into a digital DataStream that can be recorded, viewed and replayed on a site laptop or directly through the strain data logger.

Safety
As there is no need to be under or around part of the structure during measurement, normal operations can generally continue without the need for restricted operating conditions or interruption to production.

Example Strain Measurement:
During dynamic strain measurement of a rail bridge, the tensile and compressive loads in the top and bottom flanges of the girders are compared to FEA modelling. This provides an additional layer of checks in order to ensure that calculations align with real world measurement.

Benefit:
Strain Measurement on Steel and concrete structures are invaluable, as many times the measured results are lower then theoretical calculations. This leads to a quantifiable method to safely revise modelling in order to ensure the provided advice is both sensible and backed by real world measurement.

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Bolt on Strain Gauges

Bolt on strain Sensor installed onto 250UC column. Area milled flat prior to installation using our portable milling machine.

Bolt On Strain Gauges are typically employed for long
term measurement and monitoring, as well
​as monitoring in harsh environments.

Application
Bolt on strain Sensors are typically applied to silos, tanks and hoppers, or as part of Logic control of large industrial equipment in which certain loads require real time monitoring ( signal output is generally 4-20ma)

Quality & Accuracy
Dependant on the supplier, installation and calibration, Bolt on strain sensors are generally quite good at producing long term, repeatable measurements.

Preparation
Pyramid Engineering carries a variety of Portable milling equipment in order to create a smooth, machines surface that does not induce torsional load into the bolt on strain gauge.
This step is critical for accurate measurement and is often not performed or not explicitly stated by manufacturers.

Limitations
The only real limitation on bolt on strain sensors is attaining a flat machined surface. Sometimes on smaller columns this is more difficult due to the footprint required by portable milling equipment. Generally speaking, columns with a web width of 200mm or wider are acceptable for machining operations.

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Data Validation

Validation of strain loading through use of loading assembly designed specifically for project requirements.

Often During Strain measurement, A test load or other method of  of setup validation is performed.
This is to ensure the integrity of the date being provided and to assist in calibration of FEA modelling.

At times, a specific loading assemblies are developed, fabricated and used as part of site activities in order to provide a dataset with known values.