Answer to Question 1
The stages in cleaning up a system are
1. recovering the contaminated refrigerant
2. changing the contaminated compressor oil
3. flushing the lines and coils
4. performing any system modifications or repairs
5. installing liquid line and suction line driers
6. evacuating and charging the system
7. operating the system and checking performance data
Answer to Question 2
Wet bulb and dry bulb temperature readings are obtained with a sling psychrometer and then compared to a wet bulb depression chart, a relative humidity slide rule, or a psychrometric chart.