Any tendency for leaking in the sample tubing or analyzer is to be avoided, as it will directly affect the accuracy of the reading. For this reason stainless steel or a similarly strong and durable material should be used for sample tubing.
Leaks can be detected by a "probe injection" of calibration gas. In this method calibration gas is injected close to, or directly at, the very end of the sample tube, and the reading is compared to that reading obtained from the routine calibration method (injection directly at the analyzer).
A discrepancy in the readings, particularly a lower "probe injection" reading, indicates a leak or problem in the sample tubing.