This section describes how to calculate the leak rate of a vacuum-decay leak verification, which is described in § 1065.345(e). Use the following equation to calculate the leak rate nleak, and compare it to the criterion specified in § 1065.345(e):

Where:Vvac = geometric volume of the vacuum-side of the sampling system.R = molar gas constant.p2 = vacuum-side absolute pressure at time t2.T2 = vacuum-side absolute temperature at time t2.p1 = vacuum-side absolute pressure at time t1.T1 = vacuum-side absolute temperature at time t1.t2 = time at completion of vacuum-decay leak verification test.t1 = time at start of vacuum-decay leak verification test.Example: Vvac = 2.0000 L = 0.00200 m3R = 8.314472 J/(mol · K) = 8.314472 (m2 · kg)/(s2 · mol · K)p2 = 50.600 kPa = 50600 Pa = 50600 kg/(m · s2)T2 = 293.15 Kp1 = 25.300 kPa = 25300 Pa = 25300 kg/(m · s2)T1 = 293.15 Kt2 = 10:57:35 a.m.t1 = 10:56:25 a.m.[79 FR 23795, Apr. 28, 2014]