Which of the following conditions is NOT typically measured for a refrigeration system?

In a refrigeration system, temperature, pressure, and voltage are crucial parameters that are continuously monitored to ensure efficient operation and system safety. Temperature readings are essential for managing the process of heat exchange in the system. Pressure measurements are critical for evaluating the performance of the refrigerant cycle, including compression and expansion phases. Voltage is necessary for monitoring the electrical aspects of the system, ensuring that motors and components are receiving the appropriate power supply, which is vital for proper functioning.

Humidity, while it does play a role in some aspects of refrigeration—such as in systems that also deal with air conditioning or dehumidification—is not a standard measurement for the performance of a refrigeration system itself. Refrigeration systems primarily focus on temperature and pressure of the refrigerant as they directly impact the cooling capacity and efficiency. Therefore, humidity is typically not a key measurement in the context of standard refrigeration system operations.