In a pressure decay test, what is typically monitored to determine the leak rate?

In a pressure decay test, what is typically monitored to determine the leak rate?

• A. The color of the tank exterior
• B. The ambient temperature near the test area
• C. The change in tank pressure (or pressure drop) over the designated test duration
• D. The humidity inside the facility

Answer: (C)

In a pressure decay test, you track how the tank’s internal pressure changes over the test duration. If there’s a leak, the pressure will drop as gas escapes; the faster the pressure falls, the higher the leak rate. By measuring the pressure versus time with a sensor, you can quantify the leak rate (often expressed as the rate of pressure decrease, or converted to a leak rate using the tank’s volume and temperature). The color of the tank, ambient temperature, or humidity in the area don’t directly indicate how fast gas is leaking, so they aren’t used to determine leak rate.

In a pressure decay test, you track how the tank’s internal pressure changes over the test duration. If there’s a leak, the pressure will drop as gas escapes; the faster the pressure falls, the higher the leak rate. By measuring the pressure versus time with a sensor, you can quantify the leak rate (often expressed as the rate of pressure decrease, or converted to a leak rate using the tank’s volume and temperature).

The color of the tank, ambient temperature, or humidity in the area don’t directly indicate how fast gas is leaking, so they aren’t used to determine leak rate.