Reliability and error estimations of mechanical shock recorders and impact indicators

There have been significant developments in the electronics industry over the past decade which have led to the development of a variety of electronic measuring devices that can be placed in packages to both record and save shock and vibration data related to shipment. Most of the earlier devices were purely mechanical in nature and used a paper graph or a visual indicator to quantify shock levels. There are many of these types of mechanical devices that are still being used today because of their low cost. This study was performed to determine the reliability and error for various types of commercial mechanical shock recorders and impact indicators. The results are presented in the form of mean per cent errors in measuring shock values. The study concluded that the Impact-O-Graph recorder measured shock values more accurately than the Impact Register and that the Omni-G, Mag 2000 and Shockranger were similar in accuracy and were better than the Shockwatch when used in a variety of packages judged to be typical for instrumented shipment.