Elgas DATCOM, Operating Instructions Manual

Page: 147 / 228

8
Metrological Features
145
volume counter at the basic conditions (V
b
) and start to be calculated from substitute pressure or
temperature values and stored in the substitute volume counter at basic conditions (V
bs
). Under
this condition, the values are not stored in the volume counter at the basic conditions (V
b
).
The device error condition occurs in these cases:
1. the measured gas pressure is outside the measuring range - a substitute pressure value ps
is used to calculate the conversion number C, or
2. the value of the measured gas pressure is not available - an alternative pressure value ps is
used to calculate the conversion number C (e.g. in case of a sensor error), or
3. the measured gas temperature is outside the measuring range - a substitute temperature
value ts is used to calculate the conversion number C, or
4. the value of the measured gas temperature is not available - an alternative temperature
value ts is used to calculate the conversion number C (e.g. in case of a sensor error), or
5. If, during the calculation of the volume under the basic conditions, the measured value "p" or
"t" deviates from the scope for the set calculation standard outside the permitted value (see
paragraph 8.3.1 and Table 20, Table 21), and at the same time "p" or "t" are not outside the
measuring range, so the substitute compressibility "C" will be used for the calculation.
Symbol Meaning
N - Pulses from the meter
kp - Gas meter constant [pulse/m3]
p - Measured gas pressure
T - Measured gas temperature
ps - Substitute gas pressure
Ts - Substitute gas temperature
V - Volume counter at measurement conditions (primary volume)