Figure 4. The peak pressures without protection material and behind different types of protection materials, measured using the rear sensor.

The peak pressure measured without protection material was 8.25±0.48 psi (n = 4). The peak pressures behind Kevlar panel, plastic tubing layer and a combination of plastic tubing layer and Kevlar panel were 5.33±0.33 (n = 3), 0.27±0.02 (n = 5) and 0.25±0.004 psi (n = 4), respectively.