Ametek 933S, Operator'S Manual

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6-34 | Model 933S UV Analyzer
When is an Auto-Setup Required / Not Required?
The Auto-Setup optimizes PMT (photomultiplier tube) gains and the
source lamp currents. After the Auto-Setup is complete, the Automatic
Lamp Control (
ALC On ) is automatically turned on. View the current
status of this function on the Optical Bench dialog box. ALC On will be
enabled when this function is on.
Auto-Setup is required when:
• The “
w: PMT signal out of range ” alarm is displayed under MC Scode
on the Status tab.
• One or both source lamps are replaced or adjusted.
• The
Lamp Max or Signal Max values have been adjusted.
• The Measuring Cell Windows and/or optics are cleaned.
• Any optical filter is replaced.
• One or both PMTs are replaced.
• The
Optical Bench board is replaced.
If a “ w: ALC out of range ” alarm is detected, the analyzer will
automatically initiate an Auto-Setup to attempt to clear this alarm without
operator input (ideal for remote analyzer locations). When this warning
is detected, the analyzer is placed into “
zero ” (Flow Control) for the A-Z
Duration ( Auto-Zero Duration , Gas Calibration dialog box) before the
Auto-Setup is initiated. If the Auto-Setup completes successfully, a normal
Auto-Zero sequence is carried out and the analyzer is then placed into
normal operation (“
w: ALC out of range ” alarm is cleared). This “self-
initiated” Auto-Setup procedure will be attempted a maximum of three
times. If the three attempts fail to return the analyzer to normal operation,
the analyzer will continue to operate with the “
w: ALC out of range ”
alarm. The analog outputs (example: concentration outputs) are held for
the entire duration of the “
w: ALC out of range ” recovery process.
If the analyzer is caught in a repeating loop of Auto-Setups, this indi-
cates the software can’t adjust PMT signals to meet the value set for
Signal Max . This is likely due to the lamps nearing their end-of-life.
As a temporary fix, decrease the Signal Max ( Optical Bench dialog
box) to complete the Auto-Setup until the lamps are replaced.
An Auto-Setup is not required as part of a preventive maintenance sched-
ule (that is, do not perform an Auto-Setup every month).

NOTE