Siemens SIPART DR22 Manual page 33

Manual
3
m /kg
Correction range
V
B
Â
A
P to P Range of pressure of the transmitter
abs.A abs.E
to  Range of temperature of the transmitter
Â
A E
Figure 1-14 Display of the correction range
This gives for the corrected flow


q = F ·K · ρ ·
Δp
B
The factor contained in the formula K · ρ
the active pressure and can therefore be ignored by the computer.
Related to the correction factor it follows:
 
A = · f (E2, E3)
Δp
The measuring ranges are normalized to the calculation state with the parameters PA, PE, tA,
tE (correction quotients start/end for pressure and temperature).
Mass flow computer, m
A = q , E2 = p, E3 = Â
m
P
absA
PA = , PE =
P
B
T
A
tA = , tE =
T
B
SIPART DR22 6DR2210
C79000-G7476-C154-03
1.5.2
Â
B



= K · ρ · ·
Δp
B

is already taken into account in the measurement of
B

with F = f (E2, E3)
2
P
absE
,
P
B
T
E
with T [K]
T A∕E∕B
B
1.5 Functional description of the structure switches
Analog input signal processing freely connected (S4 = 1)
P P
q
abs.A abs.
bar
ρ
Δp Active pressure
p
Â
P
abs.B
T
V
R
F
P
abs.E
Indices:
A
Â
E
B
Â
E
_C
abs Absolute variable
m
v
T · p
B
P · T
B

(PE − PA) E2 + PA
=
(tE − tA) E3 + tA
1 Technical Description
Flow
Density
Pressure
Temperature (_C)
Temperature (K)
Specific volume
Gas constant
Correction factor f (p, T)
Start
End
Calculation state
Ground
Volume
31