Obtaining a representative sample of liquified refrigerant and assaying its composition

A system for sampling and assaying refrigerant fluid from a refrigerating machine, said system comprising:

• an inlet to receive refrigerant fluid from said machine;
• a control valve to enable or to prevent flow of refrigerant into the system from said inlet;
• a filter/deacidifier for removing particles and acids from said fluid;
• an oil separator to remove oil from said fluid;
• an oil recovery tank for receiving oil from said separator;
• a filter/dryer receiving fluid which has passed through said filter/deacidifier and said oil separator;
• a pump receiving fluid which has passed through said filter/dryer, said pump delivering said refrigerant in its liquid state;
• a first selector valve having an inlet port receiving said liquid refrigerant from said pump;
• a refractive index analyzer having an inlet and an outlet;
• a recovery tank;
• said first selector valve being so constructed as selectively to direct fluid from its said inlet port to said inlet port of said analyzer or to said recovery tank;
• a second selector valve having an inlet port connected to said outlet port of said analyzer and a first outlet port connected to said recovery tank, and having a selectible closed position preventing flow through said second selector valve;
• said refractive index analyzer having the capacity to assay the contents of a sample for the purpose of learning the identity and proportions of the refrigerant gases in said sample, utilizing refractive index techniques on a liquid sample;
• said sample being prepared by directing liquid sample through the first selector valve into the analyzer while said second selector valve is closed;
• said sample being removable from said analyzer by opening said second selector to permit flow into said recovery tank.