1. Grain Bin Entrapment – Pressure Measurement Kevin Moore Biosystems and Agricultural Engineering Oklahoma State University

2. Grain Bin Entrapment Entrapment – an individual is trapped inside a grain storage structure and cannot free themselves Causes Flowing grain Collapse of “bridged” grain Collapse of vertical grain wall Failure of storage structure http://www.ag.ndsu.edu/pub s/ageng/safety/ae1102.pdf

3. Grain Bin Entrapment http://extension.entm.purdue.edu/grainlab/content/pdf/2013SummaryFinal.pdf

4. Grain Bin Entrapment http://www.agriview.com/news/crop/bushels-of-risk-involved-with- flowing-grain/article_da7612f4-2a99-11e2-a78b-0019bb2963f4.html

5. Objectives Measure the pressure on the chest and back of an entrapment victim Investigate differences in grain type and depth

6. Treatments Four grain depths Top of shoulders Top of head One foot below surface Two feet below surface Four grain types Soybeans Wheat Corn Canola

7. Tekscan Pressure Measurement http://www.tekscan.com/products

8. Tekscan CONFORMat System 18.5in x 18.5in sensing area with 1,024 “sensels” Sensels are force sensitive variable resistors Pressure measurement at each sensel location Pressure map

9. Test Procedure 1.83m (6ft) hopper bin Load grain to desired depth, record pressure, unload grain Repeat for each replication and depth

10. Sensor Output

11. Mean Pressure

13. Calibration Challenges Required prior to testing for each grain Equilibration with vacuum bladder Calibration load applied with Instron Two point power law calibration curve in CONFORMat software

14. Calibration Challenges Mistake in entering calibration load Significant deviation in results Calibration is critical to data quality!

15. Future Work Complete testing with corn and canola Model behavior with PFC3D Investigate physiological response to measured pressures Funding for this research was supported by the Southwest Center for Agricultural Health, Injury Prevention and Education through Cooperative Agreement #U54-OH7541 from CDC/NIOSH

16. Questions?