The slope of the second plateau in the leak test for the quat pump of our Agilent 1100 fails. We are getting a negative slope of -2.18. Pressure and slope for the first plateau passed. Pressure for second plateau passed but the slope was negative giving a failure. The pressure value passed at 389 and the final pressure drop passed at 1.5. Any ideas of the source of failure or causes of negative slope for our leak test evaluation? Thank you.