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
n leak, 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 m 3 R = 8.314472 J/(mol ·
K) = 8.314472 (m 2 · kg)/(s 2 · mol · K) p2 = 50.600 kPa =
50600 Pa = 50600 kg/(m · s 2) T2 = 293.15 K p1 =
25.300 kPa = 25300 Pa = 25300 kg/(m · s 2) T1 = 293.15 K
t2 = 10:57:35 a.m. t1 = 10:56:25 a.m. [79 FR 23795, Apr.
28, 2014]