RKI Instruments EAGLE 2 Manual - Manual (Page 24)

14 • Instrument Description EAGLE 2 Operator’s Manual
Flow System
The EAGLE 2 flow system consists of the inlet fitting, hydrophobic filter,
pump, internal tubing, differential pressure (DP) switch, sensor chamber,
charcoal filter, and exhaust fitting.
Inlet Fitting
The inlet fitting is on the right front (when viewed from the front) of the
bottom case. It is a nickel plated brass quick connect fitting. It mates with
either the sample hose or with the hydrophobic probe.
Hydrophobic Filter
The hydrophobic filter is located in the bottom case above the sensors.
Normally the hydrophobic probe accessory (see “Hose and Probe” on
page 15) will prevent water and particulate contamination from entering the
flow system, but if the probe is not used, the hydrophobic filter will stop
water and particulates from penetrating further into the flow system. If it
becomes dirty or water logged, replace it (see “Replacing the Hydrophobic
Filter” on page 77).
Pump
A diaphragm pump inside the rear of the bottom case draws the sample to the
sensors. It can draw sample from as far as 125 feet from the EAGLE 2.
CAUTION: Sample hose lengths of more than 125 feet are not recommended
for the EAGLE 2 because of flow rate reduction and increased
response time. Consult RKI Instruments, Inc. for sample hose
lengths longer than 125 feet.
Internal Tubing
The flow system includes polyurethane tubing to route the sample between
the various components of the flow system. The internal sample tubing is not
user serviceable.
Differential Pressure (DP) Switch
The DP switch is inside the front of the bottom case. It senses the EAGLE 2’s
flowrate by monitoring the pressure drop between points in the flow system.
When the flowrate becomes too low for safe operation of the EAGLE 2, a set
of contacts inside it open and the EAGLE 2 indicates a low flow alarm.
Sensor Chamber
A PVC block in the bottom case is configured to accept the four gas sensors.
It routes the sample to each sensor. The LEL sensor and the oxygen sensor
are retained in the sensor chamber by brackets. The CO and H
2
S sensors are
each pushed past two sealing O-rings into the chamber and are retained by