Teledyne 3000ZA-3X - Trace oxygen analyzer - Manual (Page 20)

Operational Theory 3000ZA-3X
Teledyne Analytical Instruments 8
One of the three sensors has been modified (0-200 ppm range) to
sense low levels of oxygen—less than 1 ppm and generate a current
proportional to the concentration. The sensor is designed for long term
stability and an operating life of 5 years.
2.3 Sample System
The sample system delivers gases to the ZrO
2
sensors, located on
the cell block, from the analyzer rear panel inlet. Depending on the
mode of operation either sample or calibration gas is delivered.
The Model 3000ZA sample system is designed and fabricated to
ensure that the oxygen concentration of the gas is not altered as it travels
through the sample system.
The sample system for the standard instrument incorporates
compression tube fittings for sample inlet and 1/4” outlet tube
connections at the rear panel. The sample or calibration gas that flows
through the system is monitored by a flowmeter downstream from the
cell. Figure 2-1 shows the piping layout for the standard model.
Figure 2-2 shows the flow diagram for sampling systems used for
the three configurations offered as options for this instrument. In the
standard instrument, calibration gases can be connected directly to the
Sample In port by teeing to the port with appropriate valves.
Figure 2-1: Model 3000ZA-3X Sample System