Additional primary factor information

Note: This section only applies to pulse and corrector meter primary factor calculations.

The primary factor is calculated as follows:

primaryFactor = Fp * Ft * Fpv2 = (Pf/Ps) * (Ts/Tf) * (Zs/Zf)

Fp is the pressure factor.

Fp = Pf/Ps

where:

• Pf is flowing pressure in pounds per square inch absolute (PSIA).

• Ps is standard pressure (14.73 PSIA).

Ft is the temperature factor.

Ft = Ts/Tf

where:

• Ts is standard temperature (60ºF converted to Rankine).

• Tf is flowing temperature converted to Rankine.

Fpv2 = Zs/Zf

where:

• Zs is compressibility at standard conditions. That is, 14.73 PSIA/60ºF.

• Zf is compressibility at flowing conditions.

When data is processed by the AVEVA Measurement Advisor system, the Primary Factor will be converted from the input unit profile to the Internal Storage units (if a conversion is required) and saved to the database.

When displaying the Primary Factor in a unit profile with base conditions that are different than Internal Storage, the Primary Factor will be converted to the viewing unit profile. When converting the Primary Factor to different base conditions, the standard temperature and pressure in the equation above are replaced by the base conditions of the unit profile.

If it has been configured, the conversion of the Primary Factor will take the setting of CD_ZRATIO_UNIT_PROFILE into account.