ENMET CD-1300-ST - Manual (Page 10)

CO
2
Sensor / Transmitter ENMET Corporation
8
6.0 Duct Sampling Option
Figure 3: Duct Sampling Schematic
6.1 Overview
The duct sampling option is used to divert a portion of the duct airflow through the CD-1300-ST Series. The difference between
the total pressure at the upstream sample port and the static pressure at the downstream return port propels the sample stream.
Minimum recommended flow rate is 200 feet per minute.
A CD-1300-ST series with the duct sample option has a sample draw adapter fitted to the bottom of its enclosure. The duct
probe assembly is connected to tubing nipples on the adapter.
6.1.1 Duct Kit Contents
❑1 dust filter, ❑1 duct probe assembly, ❑2 sheet metal screws, ❑2 lengths of 1/8” ID tubing
6.1.2 Duct Kit Installation
1. Select a point along the duct where the probe assembly can be installed into unrestricted airflow without interfering with any
internal duct components such as dampers, radiators, etc.
2. Mark and drill the four holes for the duct probe as shown in Figure 4. The centerline must be parallel to the air flow through
the duct.
3. Install the duct probe assembly through the holes just drilled. The sample port must be on the upstream side. Secure the
probe assembly in place with the two sheet metal screws.
4. Connect the open ends of the two tubes from the probe assembly to the two sample ports on the base of the CD-1300-ST
Series. It makes no difference which tube is connected to which port on the CD-1300-ST series .
Figure 4: Duct Probe Installation Dimensions
A IR F LOW
1/8’’ ID Tube
Air Flow
5/8’’
Drill 9/64’’
(Typ. 2 plcs)
Drill 5/16’’
(Typ. 2 plcs)
1 1/4’’
2 1/2’’
1 11/16’’
1 5/16’’ 1 5/16’’
1/2’’
3’’