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3001002 Rev. P
Section 6
Initial assembly
Certain accessories must be installed in the Precision Flow
®
unit before it can be used. These
will normally be supplied in a separate package from the main unit as some are country-
specific.The power cord plugs into the IEC60320-compliant receptacle on the rear panel.
6a. Oxygen sensor installation
CAUTION
: The oxygen sensor is in a sealed
package. Un-sealing the package admits oxygen
to the sensor, which should be replaced after 1
year. Do not open the package until the unit is to
be used. Write the expiration date on the oxygen
sensor cell.
1. Remove three (3) securing screws from the access
panel.
Pull the panel away from the unit.
2. Insert the threaded end of oxygen sensor into port,
and screw into place. Sensor should be hand-tight only.
Do not use tools.
3. Plug sensor cable into connector. Replace cover.
Do not over-tighten screws.
6b. Inlet gas filter trap assemblies.
Gas filters and traps are supplied in a separate container with the O
2
sensor and must be
installed before first-time use. The filter and trap assemblies have a quick-disconnect fitting
which connects to the main unit, and a DISS gas fitting for either an oxygen or an air hose.
Note: The quick-disconnect tubes for the oxygen and air filters are different sizes, so that they
can not be connected incorrectly.
WARNING:
Never attempt to run the Precision Flow
®
unit without the inlet gas filters.
Particles in the inlet gas flow will cause irreparable damage to the mass flow sensors.
Installing the gas inlet filters
1. Remove any protective tape from the gas inlet connectors at the back of the main unit.
2. Push the filter assembly firmly in the correct connector opening until it is fully engaged
and it clicks. The filter can rotate but not pull out. Filter bowls should be vertical (glass
side down) when in use.
Removing gas inlet filter assembly from main unit
Note
: It is not normally necessary to remove the filter and trap assemblies, but shipping and
packing are easier if the filters are detached first.
1. Press the filter assembly into the main unit.
2. Hold the locking ring in place and push it back against the main unit backplate.
3. Pull the filter assembly straight out.
Oxygen Sensor Access Panel
