Micro Motion CDM100M, Configuration And Use Manual

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density. This value is used to calculate specific gravity. The result of the specific gravity
calculation is then used in the equations used to calculate °Baumé, °Brix, °Plato, or
°Twaddell.
Specific gravity is always calculated using the two reference temperatures that are
specified during concentration measurement configuration.
If you are measuring in °Baumé, the meter will automatically select the appropriate
equation according to the specific gravity of the process fluid, and will switch equations
when specific gravity crosses 1.0.
Equations used for specific gravity, °Baumé, °Brix, °Plato, and °Twaddell Table 4-9:
Equation
Current value of
specific gravity
Equation
Specific Gravity N/A
SG =
ρ
RefTemp
ρ
WaterRefTemp
°Baumé
1.0 or greater
(°Baumé heavy)
°Baumé = 145 −
145
SG
Less than 1.0
(°Baumé light)
°Baumé =
140
SG
− 130
°Brix N/A
°Brix = 318.906 −
(
384.341
SG
)
+
(
66.1086
SG2
)
°Plato N/A
°Plato = (668.72 × SG) − 463.37 −
(
205.347 × SG
2
)
°Twaddell N/A °Twaddell = 200 × (SG − 1)
SG Specific gravity of process fluid
ρ
RefTemp
Density of process fluid at Reference Temperature for Referred Density , as measured
using the active concentration matrix
ρ
WaterRefTemp
Density of water at Reference Temperature for Water
Related information
Set reference temperature values for specific gravity using ProLink III
Set reference temperature values for specific gravity using the Field Communicator
4.7.5 Matrix switching
Matrix switching can be used to measure different process fluids without resetting the
active matrix manually. Matrix switching can also be used to increase measurement
accuracy.
When matrix switching is enabled, the meter automatically switches between the matrices
in Slot 1 and Slot 2 whenever an extrapolation alert is present for the active matrix but
would not be generated by the other matrix. For example:
Configure process measurement
Configuration and Use Manual 71