For instance, not every operator may know why measurements such as Young’s Modulus, Yield Strength, Ultimate Tensile Strength, or Work are being collected or how these measurements impact the product being tested. However, having tolerances built into the test method creates a flag to notify a member of a quality team when the measurements deviate. There are also testing scenarios where individual data points are not sufficient. For example, when testing welded or stitched seams and adhesives in a 90 or 180 degree peel test, tolerances may be specified for a maximum allowed load or minimum allowed load over the length of the seam.
Creating a “tolerance envelope” can help operators quickly identify out-of-tolerance areas in peel or seam testing. The black trace above can be seen dipping below the specified minimum load as represented by the red line. The green trace is shown in tolerance for the specified area.
A tolerance envelope will ensure the seal remains in the range, where using individual tolerance points risks an out-of-tolerance point being missed. If the graph trace stays within the envelope, the tolerance lines display green, indicating that the measured results are within the envelope. If the graph trace goes outside the envelope at any point, the tolerance line segment displays red. If the data for the results are outside the high limit, the top line segment will display red. If the data for the result are outside the low limit, the bottom line segment will display red. Comments and Reports For Traceability Adding comments after a run is complete is an often overlooked tool. Rather than deleting data and leaving the possibility of future questions regarding the data integrity, comments can be used to explain anomalous results that would skew a batch. Examples of these comments could be; “sample slipped during testing” or “sample broke at grip”, as opposed to breaking-in a controlled area of a dog bone sample. Life science applications, such as those being used by medical device manufacturers and pharmaceutical manufacturers looking to meet 21 CFR Part 11, may require electronic signatures in their applications and other data protection tools. To be compliant, these operators mark data for deletion but do not actually remove it. For example, when a run is attempted to be deleted it will have a strikethrough, and a comment is automatically added to the data table showing “Deleted by User on [date]”. Alternative options like “Delete Last Run” exist as well. When enabled, only the last run of a batch may be deleted. Further to force and distance data, force and material measurement equipment is designed to measure other information and can automatically export reports for traceability purposes. For example, it is common to include date, time, operator, and batch number. Other information less commonly factored in but extremely valuable nonetheless, can help prove the materials were tested as specified such as speed, target distance, target load, number of cycles, sampling rate, and whether a test method is protected against edits.
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