What is the range of a throttling calorimeter?

The correct choice accurately reflects the operational characteristics of a throttling calorimeter, which is used to measure the enthalpy changes of a fluid as it undergoes a throttling process. In this device, the fluid typically experiences a pressure drop while its temperature increases, allowing for the determination of specific properties such as quality (dryness fraction).

The range stated in the correct choice indicates the varying dryness fractions at different pressures, specifically from .965 dryness at 700 kPa down to .93 at 2700 kPa. This suggests that as the pressure increases, the ability of the calorimeter to measure the quality of steam can be affected, thus demonstrating a decrease in the measured quality. This range highlights the calibration and performance levels of the throttling calorimeter across a relevant operational pressure spectrum, emphasizing its functional limits in high-pressure steam applications.

Understanding this range is critical for engineers when designing systems that involve steam and heat transfer processes, ensuring accurate measurements during operations. The specific values provided are derived from empirical data on the performance characteristics of throttling calorimeters at various pressures.