Sensitivities and Issues with Arc Ratings and ASTM F1959 Clothing Tests

A set of ASTM F1959 fabric tests provided a useful set of data for a deeper review of the test procedure and setup for testing arc-rated fabrics. The arc thermal performance value (ATPV) rating is sensitive to the assignment of time zero for the Stoll curve relative to the temperatures measured on the calorimeters. The ATPV rating is sensitive to errors in the panel sensor results. Because the panel sensors are averaged to represent the fabric performance, neither one represents the worst case. The location of the monitor sensors relative to the panel sensors compounds this problem. The monitor sensors (which are also averaged) may not accurately represent the energy delivered to the fabric above the panel sensors. Results for fabric tests varied significantly. An alternative rating approach is investigated to reduce variability. These results point to a need to consider changes to F 1959 or alternative approaches to obtain more consistent ratings.