Rationale

During discussions at the October 2023 E06.22.17 task group about tolerancing the air pressure cycles, it was agreed to investigate a tolerance on the 0.0 Ppos and 0.0 Pneg requirement after much discussion that every cycle must meet the minimum and maximum pressure for each cycle. For a system to meet the minimum of 0.0 psf absolute in the system within the required timeframe, it would be necessary to put an opposite load (negative during the positive loading, or positive in the negative loading) which could be more detrimental to the test specimen that the standards intent. The intent of this revision is not to change the purpose or rigor of the standard but clarify the minimum requirements to address the intent and add a tolerance to reliably meet the standard. Rather than add a tolerance to the 0.0P where the pressure is always 0.0, a psf was chosen rather than a tolerance to simplify the chart. The 1 psf rating was selected for the task groups discussion. When looking at the tolerances allowed for air pressure measuring apparatus of +/-2% of maximum rated capacity, or 2 psf, whichever less.