RMG ERZ2000-NG, Operating Manual

Page: 284 / 454

7 Parameter of the gas
Manual ERZ 2000-NG · EN07 · 2019, May 13th
274
x
GERG 88 S set B
x
GERG 88 S set C
x
AGA8 Gross Meth.1
x
AGA8 Gross Meth.2
x
AGA NX 19 L
x
AGA NX 19 H
In order to be able to apply GERG 88 S, the calorific value (Hs) and standard density
(sd) of the gas must be known and the share of carbon dioxide (CO
2
) and the share
of hydrogen (H
2
) of the gas composition must be known. In the American sphere, this
corresponds to AGA 8 Gross Method 1.
If, in addition to the calorific value (Hs) and standard density (sd), the share of hydro-
gen (H
2
) and the share of nitrogen (N
2
) of the gas composition are known,
GERG 88 S set B can be used.
If, in addition to the standard density (sd) the share of carbon dioxide (CO
2
), the
share of hydrogen (H
2
) and the share of nitrogen (N
2
) of the gas composition are
known, GERG 88 S set C should be applied. In the American sphere, this corre-
sponds to AGA 8 Gross Method 2.
Note
Strictly speaking, GERG 88 S is an extension of the AGA 8 Gross Methods for
the case that the share of hydrogen H
2
cannot be disregarded (H
2
> 0). The
AGA 8 Gross Method only corresponds to GERG 88 S if there is no hydrogen in
the gas (H
2
= 0).
A revised AGA 8 as AGA NX 19 L finds application specifically for L-gas (natural gas
with a low energy content). Another revision, AGA NX 19 H applies for H-gas (natural
gas with a high energy content).
More extensive knowledge of the gas composition is necessary for the following
methods, which, for example can be provided by a gas chromatograph.
x
AGA 8 (1985)
x
AGA 8 92DC
AGA (85) from 1985 is a first description of a gas in consideration of the individual
gas components. This model is practically never used any more.