Flowmetrics 922-MFC Installation And Operating Instructions Manual page 71

CALCULATING THE C FACTOR:
(Coefficient of Expansion)
The liquid density is a function of the flowing temperature for many fluids.
This unit solves an equation which represents this physical property of the
fluid.
The information which the unit uses to describe the fluid is entered by the user
in the following variables: Reference Temperature, Reference Specific Gravity,
Expansion Coefficient
This information is available for many fluids in one or more of the following
forms:
Fluid Specific Gravity vs. Temp. Table
Specific Gravity vs. Temp. Graph
Fluid Density vs. Temp. Table
Fluid Density vs. Temp. Graph
Begin by obtaining one of the fluid properties for the fluid you are using from
available manufacturers information or Engineering Handbooks. In some cases
this information is listed on the Material Safety Data Sheet for the fluid.
Two temperature-specific gravity pairs will be required to compute the tem-
perature coefficient.
The reference temperature is simply chosen by the user. Common reference
temperatures are 60° F or 15° C.
However, for cryogenic fluids, the normal boiling point may also be used. In
some cases the fluid data may list properties at 100° F, this temperature may
also be used as the reference temperature.
The reference temperature should be chosen so that it is in the application
temperature range. i.e. application temperature range -10 to 120° F, reference
temperature of 60° F chosen.
Enter the reference temperature you have chosen at this point.
The reference specific gravity corresponds to the fluid SPECIFIC GRAVITY
(not Density) at the reference temperature chosen.
You must convert the fluid density information to specific gravity if it is in
units other than specific gravity. Use EQ1.
EQ1.
Given the reference temperature, reference specific gravity, a second temp. and
a second Spec.Grav., the C Factor can be computed as follows:
EQ2. Used for Liquid Corrected Volume Equation
EQ3. Used for Liquid Mass and Heat Equations
Spec.Grav. = Density of Fluid / Density of Water
[
1 - (Spec.Grav.2 / Ref.Spec.Grav.)
C =
Temp.2 - Ref.Temp
√
[
1 - (Spec.Grav.2 / Ref.Spec.Grav.)
C =
Temp.2 - Ref.Temp
6-6
]
x 1,000,000
]
x 1,000,000