Span Failure; The Alarms Function - Teledyne 3000ZA2G 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 sensor at the end of the span.
The output signal decreases approximately 50 mV per decade increase in
the oxygen concentration. The software analyzes the change in output
and will trigger a span failure message if it is found differ significantly
from the 50 mV/decade value. When this occurs, the span will not be
accepted. The analyzer will return to the previous calibration values and
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 typical cause for span failure is by feeding the wrong span gas
during calibration or entering the wrong value. It can also be triggered
by an electronics failure.

4.5 The Alarms Function

The Model 3000ZA2G is equipped with 2 fully adjustable
concentration 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
Teledyne Analytical Instruments
#### % Span
Slope=#### ppm/s
Span Failed!!
Operation
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