I've lowered the alarm level for PT120B (BSC2) from 2.0e-06 to 2.0e-07. Two day trend of PT120 attached shows last nights excursion
Config:
Channel name="H0:VAC-LY_Y1_PT120B_PRESS_TORR" low="1.0e-10" high="2.0e-07" description="VE gauge, PT120B BSC2 CC"