Automotive air-conditioning servicing system and method

Apparatus for servicing air-conditioning systems, comprising:

• means for measuring the high and low side pressure of an air-conditioning system;
• means for converting said high and low side measured pressures to electrical signals corresponding to said measured pressures;
• electronic processing means for receiving said electrical signals and for comparing said electrical signals with data representing standard values for the proper functioning of said air-conditioning system;
• and
• output means connected to said electronic processing means for providing an output indicating whether said system is functioning properly and if said system is not functioning properly, for indicating possible causes of the malfunction and the procedure to be followed by the operator to effect repair of said system.

A method of recharging an air-conditioning system, comprising:

• determining the amount of oil or refrigerant to charge the air-conditioning system;
• supplying oil or refrigerant to the air-conditioning system through a fixed orifice;
• measuring the oil or refrigerant pressure on each side of the fixed orifice during a plurality of intervals of time;
• determining from said measured pressures the flow rate of oil or refrigerant through the orifice during each short interval of time and the total flow of oil or refrigerant through the orifice in each short interval of time;
• and
• subtracting the total flow of oil or refrigerant through the orifice in each short interval of time from the amount of oil or refrigerant, respectively, needed to charge the air-conditioning system until a zero quantity is reached and terminating the oil supply.

An apparatus for servicing one of a plurality of different automotive air-conditioning systems, comprising:

• a cabinet,
• said cabinet including
• first and second means for measuring the high and low side pressures, respectively, of said automotive air-conditioning systems;
• an oil storage means;
• refrigerant storage means;
• fluid-delivery means coupled to said refrigerant and said oil storage means for charging said systems with refrigerant and oil from said refrigerant and oil storage means, respectively;
• means for evacuating said systems;
• means for connecting said first and second pressure-measuring means, said charging means and said evacuating means to said air-conditioning systems;
• a microprocessor;
• means for entering information and said high and low side pressures into said microprocessor, said microprocessor providing means to analyze said information and high and low side pressures, to compare said high and low side pressure values with standard values provided by a data-storage means representing proper functioning of said system and to analyze said information and comparison and determine possible causes of malfunctions of a connected air conditioning system and a procedure to effect its repair;
• and
• output means connected to said microprocessor for indicating whether said system is functioning properly and, if not, for indicating possible causes of a system malfunction and the procedure to be followed by the operator to effect repair of said system.