Teledyne 3300PA - Low cost percent oxygen analyzer - Manual (Page 21)

3-5
Percent Oxygen Analyzer Installation 3
Teledyne Analytical Instruments
atmospheric pressure. Restricting the sample vent line will result in pressur-
izing the sensor and altering the O
2
reading.
The pressure required will depend on the sampling system. When
venting into a constant pressure, such as the atmosphere, controlling input
pressure is simple. If you are venting into a system of varying pressure, then
some form of pressure regulation is required.
Figure 3-3: Piping Diagram
3.4.1 Vacuum Service Option
For vacuum service plumbing reference figure 3-4. The vacuum
service option is recommended for applications in which the sample source is
not pressurized. The customer must supply a pump and bypass system to
complete the sample system. The sample inlet and outlet pressure must be
maintained at a constant pressure for proper performance. If the sample inlet
or vent pressure will not be held constant during the process, a pressure
regulator must be used to regulate the pressure across the cell.
Adjust the flow rate on a vacuum service system as follows:
Select Sample with the three-way control valve and open the flow
control valve on the analyzer to full flow (located on the analyzer flow
meter). Open the pump bypass valve, and turn on the pump. Readjust the
(standard piping diagram for positive pressure service)