Thermo Scientific Sarasota SG901, User Manual

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Thermo Fisher Scientific Sarasota SG901 User Guide
F-1
Appendix F
Configuration Considerations when
Using Sarasota CM515
When the Sarasota CM515 density converter is used in a Sarasota SG901
with frequency output system, the density converter can be configured to
use different formula schemes to deal with gas compressibility, Critical
Pressure, and Critical Temperature parameters. This appendix explains the
different formula schemes available in the density converter and shows the
basic configuration (in metric) of the Sarasota SG901 / CM515 system.
When using the Sarasota CM515 for D-ref (Density at Reference), MW
(Molecular Weight) or SG (Specific Gravity) measurement, the user has a
choice of which equations the converter will use for its calculation.
The equations available in the Sarasota CM515 are briefly described below.

Ideal Gas: The ideal gas laws are implemented. No compensation is
made for gas compressibility (ideal gas law deviations).

Redlich Kwong (RK): The RK equation of state is implemented.
The user must enter an isentropic exponent, critical pressure, and
temperature for the gas or an average isentropic exponent and a
quasi critical temperature and critical pressure for a gas mixture.

Soave: This is a modification to RK and can give slightly better
results. The user must enter an isentropic exponent, an Acentric
factor, and a critical pressure and temperature for the gas or an
average isentropic exponent, an average Acentric factor, and a quasi
critical temperature and critical pressure for a gas mixture.

Peng Robinson: This is another variation. The user must enter an
isentropic exponent, an Acentric factor, and a critical pressure and
temperature for the gas or an average isentropic exponent, an
average Acentric factor, and a quasi critical temperature and critical
pressure for a gas mixture.
It is suggested that either the Ideal or Soave equation is selected depending
on the accuracy required and the gas data available.
Purpose
Equations