Sierra Instruments Instruction Manual
Smart-Trak
®
2 Series 100
73
Appendix A: Gas Tables
Smart-Trak 2 Pre-programmed Gases: Dial-A-Gas
The following gases have been programmed into the Smart-Trak 2 instrument in
this order. If you are using one of these gases, you may use the Dial-A-Gas feature
in either the Pilot Module or the Software Package and the instrument will adjust
the outputs automatically.
1.
Air
2.
Argon
3.
CO2
4.
CO
5.
Helium
6.
Hydrogen
7.
Methane
8.
Nitrogen
9.
Nitrous Oxide
10.
Oxygen
K-Factor Calculations--
Using Smart-Trak 2 with Other Gases
If you will be using Smart-Trak 2 with a gas not on this list, you may use the tables
below. They provide K-factors and thermodynamic properties of gases commonly
used with mass flow meters and controllers. This is particularly useful if the actual
gas is not a common gas or if it is toxic, flammable, corrosive, etc. The tables can
also be used to interpret the reading of a flow meter or flow controller that has been
calibrated with a gas other than the actual gas.
Before applying the tables, set the instrument for Air. Then, the following fundamental
relationship may be used:
Q
1
/Q
N
= K
1
/K
N
Where:
Q =
The volumetric flow rate of the gas referenced to standard
conditions of 0°C and 760 mm Hg (sccm or slm),
K =
The K-factor from the following tables, referenced to Air
( )
1
= Refers to the “actual” gas, and
( )
N
= Refers to the “reference” gas, Air in this case.