Application of Computers in Textile:
The incorporations of computers and microprocessors has brought great changes to the instrumentation used for testing textiles. Their use falls into two main categories: Recording and calculation of results and automation of the test procedure. Both of these uses may be found in the most advanced instruments.
In these applications the computer is usually connected via an analogue to digital converter to an existing instrument from where it collects the data that would previously have been written down on paper by the operator. The advantages of such an installation are as follows:
More Consistent Measurement:
In the case of a graphical output the whole of the curve is recorded numerically so that results such as maxima, areas under the curve and slopes can be calculated directly without having to be read from a graph. This allows a more consistent measurement of features such as slopes which would previously have been measured by placing a rule on the graph by eye. However, it is important in such applications to be clear what criteria the computer is using to select turning points in the curve and at what point the slope is being measured. It is useful to have visual checks on these points in case the computer is making the wrong choice.
Adjustment of Zero Level:
The ability to adjust the zero level for the instrument automatically. This can be done, for instance, by taking the quiescent output as being the zero level and subtracting this from all other readings.
Ability to Calculation:
The ability to perform all the intermediate calculations together with any statistical calculations in the case of multiple tests.
The ability to give a final neatly printed report which may be given directly to a customer.
It is important, however, to be aware of the fact that the precision of the basic instrument is unchanged and it depends on, among other things, the preparation and loading of the sample into the instrument by the operator and the setting of any instrumental parameters such as speed or range.
Automation of the Test Procedure:
Use of Electronic Processing Technology:
In such applications use is made of electronic processing power to control various aspects of the test rather than just to record the results. This means that steps such as setting ranges, speeds, tensions and zeroing the instrument can all be carried out without the intervention of an operator. The settings are usually derived from sample data entered at the keyboard. In the case of yarn-testing instruments can all be carried out without the intervention of an operator. The settings are usually derived from sample data entered at the keyboard. In the case of yarn-testing instruments the automation can be carried as far as loading the specimen. This enables the machinery to be presented with a number of yarn packages and left to carry out the required number of tests on each package.
Repeatability of Test Results:
The automation of steps in the tests procedure enables an improvement to be made in the repeatability of test results owing to the reduction in operator intervention and a closer standardization of the test conditions. The precision of the instrument is then dependent on the quality of the sensors and the correctness of the sample data given to the machine. The accuracy of the results is, however, still dependent on the calibration of the instrument. This is a point that is easily overlooked in instruments with digital outputs as the numbers have lost their immediate connection with the physical world. If the machine fails in some way but is still giving a numerical output, the figures may still be accepted as being correct.
Example of Computerized Textile Testing Instruments: