Greetings, I have recently been given a problem to solve and I am not quite sure how to tackle it. The production group where I work uses vacuum chambers to dry 96 well plates. For sometime they were using 4 chambers all connected to the same pump. Recently they purchased a large chamber, equal in volume to the 4 small chambers, they are using the same size pump and the vacuum gauge reads -28.9 inches of Hg. However after the pump has been running for 16 hours the relative humidity is 80% in the large chamber and is practically 0% in the smaller chambers. This is my first day on this project and wanted to get some ideas before beginning. My thoughts are as follows and hopefully are right, or pointed out as wrong before I make myself look foolish. 1) The tubing going to the smaller chambers is much smaller(ID) than the tubing being used on the larger chamber. Is it possible that this increases the suction in the chamber? 2) The smaller chambers have baffles over the exit port where the pressure is coming out of the chamber, does this in some way affect the suction? 3) Would it be reasonable to bring the chamber to vacuum and then back fill with nitrogen, and then repeat the process until the plates are dry? 4) The large chamber has one large exit port, each of the small chambers has one small exit port. Would making more exit ports in the larger chamber improve air flow and therefor reduce the humidity faster? Any help will be greatly appreciated.