Helmets shall be conditioned to one of the following environments prior to testing in accordance with the test schedule at §1203.13. The barometric pressure in all conditioning environments shall be 75 to 110 kPa (22.2 to 32.6 in of Hg). All test helmets shall be stabilized within the ambient condition for at least 4 hours prior to further conditioning and testing. Storage or shipment within this ambient range satisfies this requirement.

(a) Ambient condition. The ambient condition of the test laboratory shall be within 17 °C to 27 °C (63 °F to 81 °F), and 20 to 80% relative humidity. The ambient test helmet does not need further conditioning.

(b) Low temperature. The helmet shall be kept at a temperature of −17 °C to −13 °C (1 °F to 9 °F) for 4 to 24 hours prior to testing.

(c) High temperature. The helmet shall be kept at a temperature of 47 °C to 53 °C (117 °F to 127 °F) for 4 to 24 hours prior to testing.

(d) Water immersion. The helmet shall be fully immersed “crown” down in potable water at a temperature of 17 °C to 27 °C (63 °F to 81 °F) to a crown depth of 305 mm ±25 mm (12 in. ±1 in.) for 4 to 24 hours prior to testing.