Ultra Trace Oxygen Analyzer Operation 4

4-17

Teledyne Analytical Instruments
gas or electronics failure could set this feature off at the end of the span.
Consider this before replacing the cell.

4.5 Switching of Sample Streams

The Model Ultra Trace 3000 may be used to monitor more than one
type of sample gas, such as nitrogen and helium, or two streams of nitrogen
containing low (less than 1 ppm) and high (500 to 1000 ppm) concentrations
of oxygen.
For these applications, we recommend the following parameters and
conditions be followed:
1. While switching streams, such as between nitrogen and helium, both
the gas streams must be made to flow continuosly even through only one
stream is going through the analyzer at one time. Failure to do so may result
in spikes in output when the dead-ended stream is switched in. For more
discussion of this, read the Technical Bulletin - TB00001, dated 3-98. This
Bulletin is available upon request from TATAI.
2. The analyzer is capable of handling the switching of streams without
effecting the sensitivity of the cell. This switching of streams between
nitrogen and helium will not require SPAN adjustment. However, care must
be taken to keep sample flow rates in the desired levels, as the flowmeter is
calibrated for air and nitrogen streams only.
3. The analyzer can withstand repeated switching of streams between
low oxygen levels of less than 1 ppm and high oxygen levels of 5000 to
1000 ppm. Again, care must be taken to ensure proper and continuous flows
at all times.
4.5.1 Special Notes on Hydrogen Gas Stream
The standard oxygen cell, Model B-2CXL, though tested in nitrogen
gas streams is expected to perform well in hydrogen streams. However, for
certain applications such as continuous monitoring of very low levels of
oxygen in hydrogen, the user may request cells that have been specifically
tested in hydrogen streams. Consult Teledyne for further details.

4.6 The

Alarms

Function

The Model Ultra Trace 3000 is equipped with 2 fully adjustable con-
centration alarms and a system failure alarm. Each alarm has a relay with a