Span Failure; The Alarms Function - Teledyne 3000TB Operating Instructions Manual

Trace Oxygen Analyzer
When the Span value displayed on the screen is sufficiently stable,
press Enter. (Generally, when the Span reading changes by 1% or less
of the full scale of the range being calibrated for a period of ten minutes
it is sufficiently stable.) Once Enter is pressed, the Span reading
changes to the correct value. The instrument then automatically enters
the Analyze function.

4.4.3 Span Failure

The analyzer checks the output of the cell at the end of the span. If
the raw output of the cell is less than 0.5 uA/ppm O
be accepted. The analyzer will return to the previous calibration values,
trigger the System Alarm, and display in the VFD:
This message will be shown for five seconds and the instrument
will return to the Analyze mode. In the upper right hand corner of the
VFD display "FCAL" will be shown. This message flag will help the
operator troubleshoot in case calibration was initiated remotely. To reset
the alarm and the flag message, the unit must be turned off by cycling
the standby key . It will reset if the next span cycle is correct.
A trace cell is unlikely to fail span. As explained before, when the
sensor reaches the end of its useful life, the zero offset begins to rise
until the analyzer finds the zero unsatisfactory. Nevertheless, feeding the
wrong span gas or electronics failure could set this feature off at the end
of the span. Consider this before replacing the cell.

4.5 The Alarms Function

The Model 3000TB is equipped with 2 fully adjustable concen-
tration alarms and a system failure alarm. Each alarm has a relay with a
set of form "C" contacts rated for 3 amperes resistive load at 250 V ac.
See Figure 3-6 in Chapter 3 Installation and/or the Interconnection
Diagram included at the back of this manual for relay connections.
Teledyne Analytical Instruments
#### % Span
Slope=#### ppm/s
Span Failed!!
Operation
, the span will not
2
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