8 • 35-3001-13-02 Carbon Dioxide/Oxygen Sample-Draw Detector
The housing door is hinged on the left side and is secured by two latches on the right side. The flowmeter and
status LEDs are visible through a window in the housing door.
Four mounting feet are attached to the back of the housing (one at each corner). Use the mounting feet to install
the housing to a vertical surface.
Sample Fittings
The sample fittings are located on the left side of the bottom of the housing. The inlet fitting is near the front of
the housing and the exhaust fitting is near the back of the housing. The sample fittings accept 1/4 in. rigid tubing.
See the Installation section on page 11 to connect tubing to the sample fittings.
Particle Filter
A particle filter with a tubing stub on one end is shipped with the instrument but it is not factory installed. If the
particle filter is installed directly to the inlet fitting, the tubing stub must be used. If the particle filter is installed
somewhere else, like at the end of the inlet line, the tubing stub can be used or removed.
Conduit Hub
One 3/4 NPT conduit hub is located on the right side of the bottom of the housing. It is used for routing wiring
into the housing by using conduit or an appropriate cable bushing.
Internal Components
This section describes the sample-draw detector’s internal components (see Figure 1). Figure 2 illustrates how
the gas sample moves through the flow system.
Flowmeter
Pump
Restrictor
Oxygen
Sensor
Particle Filter
Flowmeter PCB
Exhaust
Sensor Flow
Control Valve
IR CO2
Sensor
Hydrophobic Filter
Pressure Switch
Inlet
Figure 2: Flow Diagram
