Siemens SIPART DR22 Manual page 34

1 Technical Description
1.5 Functional description of the structure switches
1.5.2 Analog input signal processing freely connected (S4 = 1)
Volume flow computer related to the operating status q
Since the volume is reciprocally proportional to the density, a volume flow computer can be
made out of this mass flow computer by changing the inputs E2 and E3.
A = q , E2 = Â, E3 = p
v
T
A
PA = , PE =
T
B
P P
absA
tA = , tE =
P
B
Volume flow computer related to the standard status q
Since the output signal is now related to the volume flow in the standard status, T
P = 1.01325 bar and no longer to the operating state, it must be corrected accordingly.
N abs
A = q , E2 = p, E3 = Â
VN
T
tA = A , tE =
T
B
P
absA
PA = , PE =
P
B
The following applies for all computers:
p to p Transmitter range absolute pressure (bar)
absA absE
T to T Transmitter range absolute temperature (K)
A E
is formed from the transmitter range Â
T(K) = 273, 15 + Â (_C)
p , T Pressure and temperature range of the calculation state of the measuring
B B
panel (absolute values)
p and T must be within the range of the transmitter; and may not be more than the factor 100
B B
away from the range limits.
PA, tA = 0.01 to 1
PE, tE = 1 to 99.99
The input rE1.1 Δp is limited to values ≥0.
If the adjustable ranges for PA, PE, tA, tE are not sufficient a linear equation can be switched in
front of the appropriate input for adaptation (function block Ar).
32
T
E
with T [K],
T A∕E∕B
B
absE
P
B
T
E with T [K],
T A∕E∕B
B
P
absE
P
B
V
VN
to  by conversion:
A E
SIPART DR22 6DR2210
C79000-G7476-C154-03
Manual
= 273. 15 K,
N