Gas Sampling Lines and Filters Disposable All gas sampling lines include a male luer connector on one end for connection to the patient circuit gas sampling port. Choice of male or female luer for machine fitting. PVC sampling lines for measurement of end-tidal CO2. Coextruded PVC/polyethylene sampling lines for precision measurement of anesthetic gases. Nafion Dryer Line for water vapor removal from sampled gases. Small SARA disc filters for placement on machine end of gas sampling lines to protect capnograph monitor from moisture. 50 per case.