PR97™ Arc Thermal Performance

Test Method

ASTM F 1959-99, Standard Test Method for Determining Arc Thermal Performance of Textile Materials for Clothing by Electric Arc Method Using Instrumented Sensor Panels

(a) Reported Weight
(b) Average of Samples Measured

ATPV - is equivalent to Arc Thermal Performance Value. The higher the value, the more insulated a person is from second-degree burns. Arc Thermal Performance Value is the minimum energy causing the predicted onset of second-degree burns.

HAF - is equivalent to Heat Attenuation Factor. The higher the HAF percentage, the more heat is blocked by the fabric. The HAF is the percentage of the total energy of the arc, which the fabric blocks or prevents from passing through. If a fabric breaks open prior to reaching the second-degree burn level then a third value, the Ebt, is calculated.

Ebt - is equivalent to break-open threshold. The energy of break open threshold is most often reported with multi-layer systems.

100% Cotton Undershirt - is recommended, because although it may burn in an arc accident, it will not melt and drip and stick to the skin as a synthetic would.