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NIOSH VIBRATION MAY 2018 • E&MJ; 45 www.e-mj.com Alimak Hek — the leader in rack-and-pinion elevators is launching a new series of traction elevators for use in challenging industrial environments. The com- pany now offers one of the world's most comprehen- sive industrial elevator product portfolio with both traction and rack-and-pinion drive technology and a wide range of car sizes and capacities — for both non- hazardous and Ex environments. With surface treat- ment corrosion classification up to C5 and ingress protection rating up to IP65, the new elevators are made for the toughest environments on the planet. www.alimakhek.com T R A C T I O N E L E VAT O R S The leader in rack-and-pinion elevators now offers traction! en of the 13 instances showed percent differences of 4.4% or less. Moreover, the a w and VDV levels show strong Pearson correlation coefficients of 0.998 and 0.981, respectively. This statistic represents the strength of the relationship between two variables. Values of the Pearson correlation coefficient range between 0 (indicates no relationship) and 1 (indicates a perfect relationship). This research showed that the iPod touch using the WBV app can serve as a low-cost tool to estimate operator WBV exposures on mobile mining equipment and demonstrates results similar to those obtained by Burgess-Limerick et al. In their 2016 ACARP project report, "Managing Whole-Body Vibration at Surface Coal Mines," Burgess-Limerick and Lynas obtained 96 vertical measurements of acceleration using the app and a commercially available vibration mea- surement device, the Svantek SV 106. They concluded that the WBV app downloaded to an iPod touch provided a 95% confidence of ± 0.07 m/s 2 for the vertical direction and their results were consistent with those they previously obtained using the app. In addition, there were some functional issues associated with data collection. For future users of the iPod touch who are interested in assessing WBV for mobile mining equipment oper- ators, please consider the following suggestions to ensure proper data collection: • Power the iPods off and on immediately before data collection as a hard reset to clear the cache and ensure they are in their most stable state. • Ensure that displays are left on when securing the iPods in place. Some iPods are able to acquire data with the screen off. • Set the Maximum Time per Sample to 20 minutes; the total sampling duration may then include multiple 20-minute samples. • Place the iPod face down on the seat near the right or left bony part of the operator's buttocks with the long dimension of the iPod perpendicular to the direction of travel. • Ensure that the tape affixing the iPod to the surface firmly secures the device. Alan Mayton is a mining engineer and Brian Kim is a mechanical engineer. Both work for the Pittsburgh Mining Research Divi- sion of National Institute for Occupational Safety and Health (NIOSH). Alan Mayton can be reached at: anm9@cdc.gov. Acknowledgements The authors thank Robin Burgess-Limerick, Ph.D., of the University of Queensland, Australia, Jonisha Pollard, M.S., and Mahiyar Nasarwanji, Ph.D., for their support and contributions to the field data collection protocol and data analysis in perform- ing this study. Disclaimer The findings and conclusions in this paper are those of the au - thors and do not necessarily represent the official position of the National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention. Mention of any company or product does not constitute endorsement by the National Insti- tute for Occupational Safety and Health, Centers for Disease Control and Prevention.