This is the vacuum system. It is used to dry the samples before they are measured. The samples are placed in the vacuum chamber. The vacuum chamber is connected to the vacuum traps by a series of vacuum hoses. One vacuum trap contains Indicating Drierite, a dessicant that will change color when exhausted. The dessicant is present to remove all water from the air being pumped from the vacuum chamber. The other vacuum trap contains glass wool to prevent oil from entering the vacuum chamber in the event of a pump failure. The vaccum traps are connected to each other and to the vacuum chamber with vacuum hoses. The vacuum pump creates a vacuum of about -85 kPa within the vacuum chamber. Samples are stored in vacuum so they will be completely dry when they are needed.