Emerson Micro Motion Configuration And Use Manual

9.8.1 Equations used in user-defined calculations
Each user-defined calculation has an equation and a set of user-programmable constants
and/or user-specified process variables.
User-defined calculation 1 (square root) Equation 9-1:
y=A + B ×
(
a ×
(
b +
(
X × c
))
d ×
(
e +
(
Y × f
))
)
A, B, X, Y
User-programmable constants
a, b, c, d, e, f
User-programmable constants or user-specified process variables
y
Result of calculation
User-defined calculation 2 (exponential) Equation 9-2:
y = e
(
A+
(
B×t
)
+
(
C×t
2
))
e
Natural logarithm
A, B, C
User-programmable constants
t
User-programmable constant or user-specified process variable
y
Result of calculation
User-defined calculation 3 (quartic) Equation 9-3:
y = A + B ×
(
ρ
B
ρ
W
)
+ C ×
(
ρ
B
ρ
W
)
2
+ E ×
(
ρ
B
ρ
W
)
3
+ F ×
(
ρ
B
ρ
W
)
4
A, B, C, E, F
User-programmable constants
⍴
W
Density of water at reference temperature and reference pressure, user-
programmable
⍴
B
Referred density from the concentration measurement application
y
Result of calculation
9.8.2 Measurement units used in user-defined calculations
The meter's internal measurement units are used for all process variables referenced by a
user-defined calculation. All constants must be entered in the internal measurement units
or derived using the internal measurement units.
Process variables and internal measurement unitsTable 9-1:
Process variable Internal measurement unit
Density g/cm³
Referred Density g/cm³
Mass Flow (external or calculated) kg/sec
Measurement support
Configuration and Use Manual 131

Emerson Micro Motion Specifications

General

Brand	Emerson
Model	Micro Motion
Category	Measuring Instruments
Language	English