System and method for injecting oil into an air conditioning circuit

An air conditioning service system comprising:

• an oil receptacle configured to store oil;
• a coupling port in fluid communication with the oil receptacle through an oil injection line;
• a first solenoid valve configured to selectively allow the oil to flow from the oil receptacle into the oil injection line;
• a second solenoid valve configured to selectively isolate the oil receptacle from the oil injection line;
• a chamber having an inlet in fluid communication with the first solenoid valve and an outlet in fluid communication with the second solenoid valve;
• and
• a pressure sensor configured to generate pressure signals associated with pressures of the chamber;
• a memory including program instructions stored therein;
• and
• a controller operably connected to the first solenoid valve, the second solenoid valve, the pressure sensor, and the memory and configured to execute the program instructions to:
• obtain at least one viscosity signal associated with a viscosity of the oil, the obtaining of the at least one viscosity signal including generating the at least one viscosity signal during a viscosity determining procedure using the generated pressure signals,
• obtain a volume signal indicative of an amount of oil to be charged,
• determine a first time period based upon the obtained at least one viscosity signal and the obtained volume signal,
• control the first solenoid valve to an open condition, and
• control the first solenoid valve to a closed condition after the determined first time period has passed since opening of the first solenoid valve.