What is the function of a leak-down test?

The function of a leak-down test is primarily to determine seal integrity by checking how quickly pressure drops within a system. This test is critical in hydraulic and pneumatic applications where maintaining pressure is essential for proper operation. During the leak-down test, a system is pressurized and the pressure is monitored over time. If the pressure drops significantly within a short period, it indicates that there is a leak or failure in the seals somewhere in the system, which needs to be addressed to ensure the system operates efficiently and safely. This method helps in identifying potential issues before they lead to more significant failures or malfunctions.

The other options do not relate specifically to the core purpose of a leak-down test. Measuring flow rate, calculating fluid volume, and assessing temperature of fluids involve different aspects of system diagnostics that do not focus on seal integrity in relation to pressure retention.