The tensometer apparatus shown below extends a sample at a constant rate, and electronically measures the displacement and the load. In order to work out the stress and strain the diameter and gauge length of the samples needs to be recorded before the test is carried out.
The specimens load into the machine as shown in the photographs below, and the machine begins to extend the specimens at a rate of approximately 3.5 mm per minute. The load and cross head displacement are recorded directly into graph form using the pen-plotter. This gives continuous data so it is easier to see the yield point than if using data from the meter at particular time intervals.
To record the data given in the results in this package a more sophisticated machine was used, which recorded the data straight onto a computer, taking readings every second, from which graphs were produced.
previous | next