MT339-I
Rev.0.3 08/04/2022
5 - 25
Document classified as: 2 - Company Confidential
1.1
Conversion coefficient
The PTZ corrector performs the acquisition of the pulses emitted by the counter meter and calculates
the equivalent cubic meters base conditions according to the formula:
Symbols
Represented quantity
Measuring unit
V
b
Volume at base conditions
m³
V
m
Volume at measurement conditions
m³
P
Absolute pressure at measurement conditions
bar
P
b
Absolute pressure at base conditions
bar
T
Temperature at measurement conditions
K
T
b
Temperature at measurement conditions
K
Z
Compressibility factor at measurement conditions
-
Z
b
Compressibility factor at base conditions
-
C
Conversion factor
-
The compressibility factor takes into account the deviation of behaviour between real and ideal gas. The
calculation method can be configured.
The flow-meter calculates the Z values according to the following standards:
•
UNI EN ISO 12213-2 (AGA8-DC92)
•
UNI EN ISO 12213-3 (SGERG88)
•
AGA-NX19
The conversion factor is calculated according the formula specified into standard UNI EN ISO 12405-1.
1.2
Energy
The device calculates the energy of gas flown according the standard UNI EN 12405-2:2012.
Symbols
Represented quantity
Measuring unit
V
b
Volume at base conditions
m³
E
Energy
J
Hs
Superior calorific value
J/m³
If the compressibility factor configured is AGA8-DC92, the Superior Calorific Value is calculated according
the standard UNI EN ISO 6976:2008, otherwise must be configured by user.
The data-logger processes the metric data according to UNI / TS 11291-3 / 4 and makes them available
to the central acquisition system (
SAC
) via
GSM / GPRS
.
