PRESSURE CHANGE II

While conducting a pressure change leakage rate test using a barometer and an ordinary pressure gage to measure the system pressure, a decrease in barometric pressure is observed. If there is no measurable leakage and the system temperature is unchanged, the system gage pressure will:

• increase by the amount of the barometric pressure decrease.
• decrease by the amount of the barometric pressure decrease.
• remain the same.
• vary the same as the system absolute pressure.

While conducting a reference system pressure change measurement test, an increase m barometric pressure is observed. If there is no measurable test system leakage, the differential pressure between the reference system and the test system will:

• increase by the amount of the barometric pressure increase.
• decrease by the amount of the barometric pressure increase.
• remain the same.
• vary the same as the system absolute pressure.

Zero degrees Kelvin (K) is about equal to:

• -360 °R,
• -170 °F.
• 0 °C.
• -273 °C.

A pressure change measurement test of a system is conducted using a pressure gage that indicates pressure with a consistent small error. The temperature during the test is constant. The effect o the results of the test is:

• to show a greater pressure loss than the actual amount.
• negligible because of cancellation of repeating error.
• to show less pressure loss than the actual amount.
• none of the above.

A temperature of 60 °F would be about the same as an absolute temperature of:

• 329 K.
• 15 °C.
• 520 °R.
• 285 °R

When a system's drybulb temperature and, in turn, total pressure, increases during a pressure change leakage rate test, the water vapor pressure in the system under test would normally:

• increase.
• remain the same.
• decrease.
• oscillate.

The purpose of performing a pressure change measurement test is to determine:

• that the component leakage rate can be measured.
• that the component meets the minimum intended service requirements.
• that preliminary leak testing was performed in accordance with the procedure.
• all of the above.

In a rigid volume pressure change measurement test system, if the system internal drybulb temperature reaches the system internal dewpoint temperature, how can this affect the system leakage rate test results?

• It will have absolutely no effect.
• Moisture condensed into the system reduces the system volume, causing an increase in system pressure not attributable to temperature change.
• When dewpoint sensors become saturated, the dewpoint temperature readings can be very inaccurate. If the situation is not accounted for in the data analysis, the leakage rate test results can be very inaccurate.
• The system will be saturated minimizing pressure variations caused by temperature changes. This reduces deviation of the data and increases the reliability of the test results.

The general gas law showing the relationship of pressure, temperature and volume of an ideal gas is expressed by which one of the following relationships?

• = constant or P1T1 = P2T2 (when V1 = V2)
• PV = nRT or P1T2 = P2T1 (when V1 = V2)
• PV = nRT or P1V2 = P2V1 (when T1 = T2)

If the pressure change measurement test for each of three different systems results in the same pressure loss for the same test time, test pressure and temperature, the leakage rates for each system would:

• be the same,
• vary directly with the volume of each system; i.e., the bigger the volume, the larger the leakage rate. \
• vary indirectly with the volume of each system; i.e., the smaller the volume, the larger the leakage rate.
• vary directly with the surface area of each system; i.e., the bigger the surface area, the larger the leakage rate.