The chamber exhaust tube on the LI-6400XT is used to route exhaust air from the sample chamber into the match valve. This tube makes a pressure seal against a small stainless steel tube on the bottom of the chamber and one on the body of the match valve. Installing this tube can be difficult and if not done properly can lead to sample chamber leaks and errors when matching. To ease installation, the ends of the exhaust tube can be flared slightly using a pair of needle nose pliers. This will widen the ends of the exhaust tube temporarily. Once in place the plastic’s “memory” will cause the ends to contract to their original size creating a tight seal.