OX-TRAN Model 2/22 Operator’s Manual
Setting Up
MOCON, Inc.
Revision R
2-5
Test Gas (Oxygen)
The OX-TRAN Model 2/22 requires an oxygen test gas with a purity of at least 99.9%. The regulator (on the
compressed gas cylinder) must be approved for oxygen use. The optional Regulator Assembly contains an
approved Oxygen Regulator. A standard T size cylinder should provide sufficient gas to operate a single
instrument for several weeks.
Carrier Gas (Nitrogen)
The OX-TRAN Model 2/22 requires a Carrier Gas mixture that is 98% nitrogen and 2% hydrogen. The
specific percentage of each gas is not critical. The percentage of hydrogen in the mixture may be as low as
1% or as high as 3%. The hydrogen is used with a catalyst in the instrument to remove any residual oxygen
in the Carrier Gas.
Compressed gas cylinders containing hydrogen require a “Hydrogen Regulator”. The tank fitting on a
Hydrogen Regulator uses left hand threads. The optional Regulator Assembly contains an approved
Hydrogen Regulator. A standard T size cylinder should provide sufficient gas to operate a single instrument
for several weeks.
Gas Distribution Systems
Each instrument ships with two local regulator/isolation devices (called Regulator Tees) that can be used to
connect the instrument to a common Test Gas/Carrier Gas distribution system. Figure 2-4 illustrates how a
gas distribution system for multiple instruments can be created using the provided Regulator Tees.
When using compressed gas cylinders, consideration should be given to the impact cylinder replacement
will have on operational efficiency. Interruptions to the gas supply when a cylinder is changed (or goes
empty) will have an adverse effect on any active tests. Cylinder manifolds that provide an uninterrupted gas
supply during cylinder replacement are available from many gas suppliers.
Figure 2-4: System Plumbing Connection Diagram