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, , and compare it to the criterion specified in § 1065.345(e):
Eq. 1065.644-1
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.
[89 FR 29808, Apr. 22, 2024]