What should a technician soif he discover that some r502 was added in a r22 system?

If a technician discovers that R502 was added to an R22 system, he should first isolate the system to prevent further contamination. Next, he should recover the mixed refrigerant using a certified recovery machine and dispose of it according to environmental regulations. After that, the technician should thoroughly evacuate and vacuum the system before recharging it with the appropriate R22 refrigerant. Finally, he should conduct a pressure and leak test to ensure the system is functioning correctly and safely.