Exam Question

### (a) Methods for Detecting Gas Leakage in Refrigeration Systems
There are several established methods for detecting refrigerant gas leakage, each with specific applications and sensitivities:
1. **Soap Solution Method:** This is a direct visual method. A proprietary leak detection solution (or soap and water) is applied to suspected leak points such as joints, valve glands, and fittings. If a leak is present, the escaping gas will form bubbles, pinpointing the exact location of the leak. It is most effective for larger leaks and requires direct access to the inspection point.
2. **Electronic Leak Detector:** These are highly sensitive portable devices that sample the surrounding air. The probe is moved slowly along system pipework and components. When refrigerant is drawn into the detector, it triggers an alarm (audible, visual, or both). Different sensor technologies exist (e.g., heated diode, infrared) which offer varying sensitivities and resistance to false alarms from other gases.