A method involves inspecting/testing a refrigeration system. One or more conduits or other components cooperate with the compressor, heat rejection heat exchanger, expansion device, and heat absorption heat exchanger to define a refrigerant flowpath. The inspecting/testing method comprises placing a plurality of collars over respective joints along the refrigerant flowpath. The collars each define a space that may be exposed to one or more sensors. Based upon input from the sensors, the presence or absence of leaks at the joints is determined.