Contrec 515 Series with GN11 application measures the volume, mass and gross heat content of natural gas. The instrument uses a frequency volume flow input and analogue temperature and pressure sensor inputs.
The instrument is compatible with a wide range of flowmeter frequency outputs. Millivolt signals, reed switches, Namur proximity switches or pulse trains can be selected via its smart front-panel programming.
The SGERG calculation (AGA-8 Detail Characterization Method) is used to obtain accurate values of density and compressibility factors for the flow calculations.
The gas density and compressibility factor calculations are based on the SGERG (AGA-8 Gross) equations. The calculations are valid for the region:
-8.0°C < t < 62.0°C P < 12MPa
17°F < t < 143.0°F P < 1740psia
Mflow = volume flow• ρflow
corrected flow = Mflow/ρ ref
Heat flow = Mflow•Hm
Mflow = mass flow
ρflow = density at flow conditions
ρ ref = density at reference conditions
Hm = mass gross heating value