Revision 1 92 9/10/2019
• Sample Delay and Sample Interval - The sample delay time and sample interval time added
together make the total analysis cycle time. The sample delay and sample interval are
used differently depending on which analysis algorithm is in use; the standard (peak
detection) algorithm of the fixed time analysis algorithm.
• Standard Analysis: In the standard analysis algorithm, the software detects the point during
the analysis where the rate of stain reaches a maximum value. At this point the
concentration of phosgene is calculated and stored until either the end of the cycle or a
different maximum value is detected. During the sample delay time the analyzer will not
search for the maximum rate of stain. The sample delay time is used to ignore the first part
of the analysis cycle where noise due to the tape advance may be present. The sample
delay will typically be 10 seconds. During the sample interval, the analyzer will be allowed
to search for the rate of stain maximum value. The sample interval will typically be 230
seconds to give a typical cycle time of 240 seconds.
• Fixed Time Analysis: In the fixed time analysis algorithm, the analyzer calculates the
average rate of stain over a fixed period of time, called the sample interval. The analyzer
will not calculate the average rate of stain during the sample delay because the rate of stain
is generally not stable during this time period. Typically the sample delay is approximately
120 to 180 seconds for the fixed time analysis and the sample interval is approximately 30 –
60 seconds to give a total cycle time of 3 to 4 minutes.
The type of analysis algorithm used will depend on the analyzer’s specific application and is
set up at the factory. The type of algorithm used and the sample delay and interval values
should not be changed without consulting the Galvanic Applied Sciences.
• Tape Saturation Cut-off (TSC) - The tape saturation cut-off is the sensor output at which the
analyzer will automatically cease the current analysis, calculate the concentration value for
the current analysis, update all outputs, advance the tape, recalibrate the sensor block, and
begin a new analysis cycle. The TSC takes precedence over the sample interval time for
completion of an analysis - that is to say, if the sensor output reaches the TSC prior to the
completion of the sample interval time, the analysis will be considered to be complete.
Thus, the sum of the sample delay and sample interval times in the standard analysis mode
is only a maximum cycle time value and the actual cycle time could potentially be shorter.
To have a better chance of the maximum cycle time being the actual cycle time, the TSC
value should be set to a very high value in the GUI (a large value is set at the factory).
Setting the TSC value to a high level makes it much more likely that the analysis time will
reach the end of the sample interval prior to reaching the TSC.
• Name Field – used to enter the name that will be displayed in the Current Analysis field in
the Analysis tab. It will also be displayed on the analyzer LCD screen when the run types
are displayed under the F1 STRM menu.
• Consecutive Runs - indicates how many times to run the Gas run before switching to the
next run in the run queue. If no other run is enabled and it is set up in the Automatic
Sequence under the sequence tab, the analyzer will simply continue running until another
run is triggered either conditionally or scheduled.
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