🔍 Key Concepts

• Superheat in a refrigeration evaporator and what it means for refrigerant state (liquid vs vapor) • Which device actually meters/controls refrigerant flow into the evaporator • The difference between controls that react to temperature in the box vs. refrigerant condition at the evaporator outlet

💭 Think About

• Which component directly senses or responds to the temperature of the refrigerant leaving the evaporator, rather than the air in the refrigerated space? • Which option is a flow‑control device for refrigerant, and which are just electrical or safety switches? • How is superheat adjusted in practice: by changing how much refrigerant you feed into the evaporator, or by changing when the compressor cycles on and off?

✅ Before You Answer

• Identify which choice is a refrigerant metering device rather than an electrical control or switch • Ask: which device has a sensing bulb or element attached to the evaporator outlet to control refrigerant flow based on superheat? • Eliminate any device that primarily controls box temperature or compressor operation, not refrigerant condition in the coil