Issue link: https://cp.revolio.com/i/617505
The answer to the question of whether a specific vibration test time correlates to actual distance traveled in shipping is YES and NO, depending on the test and the shipping means. YES, under certain specific conditions. NO, for many common packaged-product tests. If the vibration test is (1) random vibration with a spectrum shape that is an accurate representation of the actual transport vibration, and (2) run for the same amount of time as the actual shipment, or time- compressed in accordance with an accepted formula, then vibration test time can be correlated to actual shipping time or distance. If either condition (1) or (2) above is not met, then the vibration test cannot be reasonably and accurately correlated to shipping time and distance. This doesn't mean that the test isn't useful, only that there is not a strong relationship to actual transport. All of the ISTA 1-Series "Non-Simulation Integrity Tests" are "not designed to simulate environmental occurrences", and therefore there is no correlation, expressed or implied, between 1-Series vibration and actual shipping times or distances. ISTA 2-Series tests are the same as the 1-Series with regard to their vibration sections, except for Procedure 2C. While 2C includes shaped random spectra reasonably representative of actual transport vibration, the test time is constant and rather arbitrary. There has been no attempt at correlation to actual ship time/distance. ISTA 3-Series "General Simulation Tests" offer the best correlations. Procedures 3B, 3E and 3H contain a formula relating to miles and kilometers to test time, so the correlation is clearly stated. ISTA Project 4AB, available to members for no additional charge through the ISTA Member Center, includes test time vs. shipping time/distance correlations. For a more complete discussion of this topic, download the paper written by William Kipp (presented at ISTACon in 2000, and revised/updated in 2008), which is available in ISTA's Technical Library: www.ista.org 16 ista views • December 2015 • www.ista.org ISTA Technical Update Q: A: Does laboratory vibration test time equate to distance traveled in shipment? Eric Hiser ISTA Vice President - Technical TECHNICAL UPDATES Annual Test Procedure Review: 3A & 3E As part of the Technical Division's yearly procedure review, a survey is forthcoming to all ISTA members seeking feedback on procedures 3A and 3E. When you receive the survey, please take a moment to provide feedback. The information will be reviewed and discussed by the Technical Division Board at their spring TransPack Forum meeting to deem if any action is required. Reminder - Updated Test Report Templates We reported last issue that all testing report templates have been updated to include a place for pictures. While at this point, pictures are not required for report submission to ISTA, it is highly encouraged. The inclusion of pictures in a test report not only enables ISTA but also any subsequent person reviewing the report, a greater understanding of the testing sequences the packaged-product encountered, packaging materials utilized, the packaging configuration, as well as the pre & post product and packaging condition. The updated report templates can be accessed through the Member Center on ISTA.org – http://www.ista.org/members/index.php