User manual
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Section 4 MC-III™ EXP Flow Analyzer
Gas Volume Correction (Supercompressibility Calculation)
Gas turbine meters are calibrated in actual cubic feet (ACF), and measure gas in actual cubic feet. In some
applications, a user may benet from referencing gas measurements back to standard conditions by measuring
in terms of standard cubic feet (SCF). The MC-III EXP makes this process quick and easy, by using xed
average values for the owing gas temperature and owing gas pressure.
By default, this option is disabled.
To access this feature, check the “Enable volume correction” checkbox in the Gas Volume Correction section
of the K-Factor Entry screen. The “STANDARD” annunciator on the LCD will illuminate, and all other Gas
Volume Correction data elds will be activated (Figure 4.26).
Figure 4.26—Gas volume correction settings on K-Factor Entry screen
Atmospheric pressure is set at 14.73 psia by default, but can be adjusted to local conditions.
To compensate the gas measurement to standard conditions, complete the following steps:
1. Enter the atmospheric pressure.
2. Enter the base pressure and unit. The base pressure is the pressure to which the gas will be compensated
(typically, 14.73 psia).
3. Enter the base temperature and unit. The base temperature is the temperature to which the gas will be
compensated (typically, 60°F).
4. Enter the working pressure and unit. The working pressure is the user-entered pressure that represents the
average working (owing) pressure.
5. Enter the working temperature and unit. The working temperature is the user-entered temperature that
represents the average working (owing) temperature.