Elgas miniELCOR, Operation Manual, Page: 11 / 131

miniELCOR
4
1.2.3 Volume correction at measurement conditions
Device enables to compensate gasmeter error according to predefined
correction curve from gasmeter test certificate. This function and parameters V
c
can
be activated only by manufacturer or by Acreditive service to ensure that used
gasmeter correction curve in dependance on flowrate Q
m
is valid within working
conditions.
Error of measurement is corrected by usage of function f(Q
m
). For corrected
volume is:
V
c
= V
m
x f(Q
m
)
where
V
c
... Corrected volume at measurement conditions
V
m
... Primary volume
Q
m
... Primary flowrate
Linear interpolation method is used for getting values between calibration
points. File with correction values is to be inserted into device with help of service
programme 22. Information about insertion of correction curve into device is logged
in setup archive.
The principle of volume calculation are seen on Fig. 1
Condition for usage of volume correction.
1. Correction is used only in case that gasmeter transmits at least 10 pulses
per second resulting in usage only HF sensors.
2. Under Q
min
correction is not applied and over Q
max
value of correction
coefficient given for Q
max
will be used.
Conversion of volume on energy (*)
Device enables to calculate consumpted quantity of gas directly in energy form.
This conversion uses value of combustion heat H
s
. Calculation is made with
adding of differences dV
b
( and dV
bs)
multiplied by actual value of combustion heat
H
s
.
dE=H
s
x dV
b
, dE
s
=H
s
x dV
bs
Two other counters ( energy counter E and estimated energy counter E
s
) are
dedicated for measurement in configurable energy units: MJ, kWh, Btu.
Note :
No conversion of absolute counter value (E or Es) is accomplished after
change of units. Following increases are added already respecting new units.
Principle diagram of energy calculation is drawn at Fig. 1