Two arc Measuring Ratings of Arc Proof Fabric, What Difference and Similarities Between ATPV Value and EBT Value? - YULONG SAFETY

Two arc Measuring Ratings of Arc Proof Fabric, What Difference and Similarities Between ATPV Value and EBT Value?

arc proof fabric

Some arc proof workwear can make the skin feel burning warning before broken, but others can not, arc proof knitted fabric is usually broken before burning, but arc proof woven fabric will be burning before broken. Thus the arc protection performance of the arc proof fabric produced two ratings. One is the ATPV value: the arc thermal performance value; the other is the EBT value: the energy of burst threshold.
Two indicators in accordance with ASTM standard arc rating is defined as follows:
ATPV value: according to the Stoll curve, it means energy incident on the material has 50 % probability that make sufficient amount of heat penetrating the sample and cause second-degree burns.
EBT value: according to the Stoll curve, it means the minimum energy incident on the unit material has 50% probability that make the sample broken.(the arc proof fabric will be broken when the hole area more than 0.5 square inch.)
ATPV value and EBT value are using the same test method (ASTMF1959) to assess, the unit are same: cal/cm2, record arc level by the value reached first.
That is: if the EBT value is equal to or less than ATPV value, "EBT" will be used and marked as arc rating ( EBT ) ; if EBT value is greater than ATPV value, "ATPV" will be used and marked as arc rating.
If the ATPV value bigger than EBT value, the arc proof fabric will be broken first, otherwise, the fabric will be burned before broken. So ATPV value and EBT value, which one can better reflect the protective property of arc proof fabric? In fact, the two rates are no good or bad. Basically, EBT fabric has better insulativity than the strength, but ATPV fabric are different. In general, EBT value indicates that the arc proof workwear is made of arc proof knitted fabric, which is more comfortable, and do does not reduce the protection of the wearer substantially.