Elster Instromet 2000 - Solartron Density Transducer Inputs

Model 2000 Flow Computer Instruction Manual
2.0 GENERAL DESCRIPTION
Model 2000 issue 21 Page No
39
2.4.8.2. SOLARTRON DENSITY TRANSDUCER INPUTS
The basic equation used for calculation of the Line density is as follows:-
1)
)T10K()T10K(K
23
2
3
10
××+××+=ρ
−−
Where
ρ : Line Density of gas in kg/m3 Equation 1)
K0 : Constant DATA ENTRY
K1 : Constant DATA ENTRY
K2 : Constant DATA ENTRY
T : Density Transducer period in µ Seconds MEASURED
The density meter measurement can be corrected for the effects of gas temperature, when this is selected the following
equation is used, if none is selected the temperature correction is preset to 1:-
2)
()
[
]
)tt(10Ktt10K1
0l
4
1901
4
18t
−×+−×+×ρ=ρ
−−
Where
ρt : Line Density of gas corrected for temperature in kg/m3 Equation 2)
K18 : Constant DATA ENTRY
K19 : Constant DATA ENTRY
t1 : Line gas Temperature in °C MEASURED
t0 : Reference gas Temperature in °C DATA ENTRY
The density meter measurement can be corrected for the effects of the velocity of sound in gas by two alternative methods.
Firstly as detailed in Equations 3, 4 and 5 as follows and alternatively as in equations 6 and 7 as follows, if none is selected
the Vos correction is preset to 1:-
3)
⎥
⎥
⎥
⎥
⎥
⎥
⎦
⎤
⎢
⎢
⎢
⎢
⎢
⎢
⎣
⎡
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛
×
×
+
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛
×
×
+
ρ=ρ
2
g
4
VOS
2
c
4
VOS
ta
CT
10K
1
CT
10K
1
Where
ρa : Line Density of gas corrected for VOS and temperature in kg/m3 Equation 3)
Kvos : Constant DATA ENTRY
Cc : Velocity of Sound in Calibration gas (See Equation 4)
Cg : Velocity of Sound in Flowing gas (See Equation 5)
It is also possible to either preset or calculate both the velocity of sound in the flowing gas and calibration gas used in this
equation, if this is selected then the following equations are used:-