🔍 Key Concepts

• Function and location of a sight glass in a refrigeration liquid line • What visual indicators (bubbles, color change) in a sight glass typically represent • Why detecting contaminants in a closed refrigeration system is important

💭 Think About

• Think about what you can realistically see through a sight glass and what that tells you about the health of the refrigerant, not the mechanical parts • Ask yourself which choice is commonly monitored using color-changing elements or indicators within the sight glass • Consider which of the listed items would require internal inspection or instruments instead of a simple viewing window in the liquid line

✅ Before You Answer

• Verify which option relates directly to the refrigerant quality or contamination, not mechanical operation • Eliminate any answer that would normally be checked with temperature or pressure gauges rather than a visual window • Focus on what condition can be shown by a color indicator or bubbles in the sight glass per standard refrigeration practice