KROHNE ALTOSONIC V EN - Manual (Page 59)

ALTOSONIC V
Operating Manual rev02 E 7.30850.34.00 Page 59 of 106
5.4 Sarasota meter density is calculated as follows:
) ( ) (
0
'
0 cal p cal t
p p N t t N T T − + − + =
) 2 (
'
0
'
0
'
0
'
0
0
T
T T
K
T
T T
D
m
−
⋅ + ⋅
−
⋅ = ρ
ρ
m
: Calculated measured mass density of fluid [kg/m 3 ]
T : Measured periodic time [µs]
T
0
‘ : Corrected value of T
0
[µs]
T
0
: Calibration factor, reference periodic time [µs] of spool at 15°C and zero density
t : Absolute temperature [K]
t
cal
: Calibration factor, calibration temperature used in density calculations [15°C]
p : Absolute pressure [bar]
p
cal
: Calibration factor, calibration pressure used in density calculations [1.01325 bar]
N
t
: Calibration factor, temperature coefficient of spool [µs/K]
N
p
: Calibration factor, pressure coefficient of density transducer [µs/bar]
D
0
: Calibration factor, calibration constant of spool [kg/m 3 ]
K : Calibration factor, spool calibration constant [ ]
The calibration factors can be altered on-line while the system is operating, by keyboard (CONTROLS
F9, DENSITO F5) or by Modbus control.
But for custody transfer reasons the write access to the density cells can be blocked in the
configuration file CLNT0300.DAT