Thanks for your reply! The capillaries in the Conflo are moving as they should be and look to be in the right position. We now also have encountered the same dilution issue with N2 and SO2. As soon as we dial the dilution up to 80% for any of the gases, the peaks disappear. We suspect that one of the He valves in in the Conflo may be malfunctioning, but it's not obvious. If anyone has seen this problem before, please let me know.