a problem that how to connect the experimental equipment with the gas detection equipment

[gc521]

This is my first time to communicate with others in English.I want ask a question that how to connect the experimental equipment with the gas detection equipment.I need to detect the gas concentration during the experiment,so I need to put the gas which generated in the experiment into the gas detection equipment.But the diameter of the gas inlet connector is so small.It is one millimeter and the diameter of the experimental equipment is about one centimeter.Please give me some help about the problem how to connect the smaller diameter with the bigger diameter,and give me some detail steps to solve the problem.Thank you very much!