ISCO 6700SR, Instruction Manual, Page: 100 / 190

6700SR Refrigerated Sampler
82
Multiple Bottle Compositing
Multiple bottle compositing is a combination of bottles-per-sample
and samples-per-bottle. At each sample event, the sampler depos-
its a sample into a set of bottles. It moves to a new bottle set only
after each bottle of the first set contains the programmed number
of samples. Use multiple-bottle compositing to collect identical sets
of composite samples or a composite sample that is larger than the
capacity of a single bottle. Multiple bottle compositing is available
only in extended programming.
Time Switching
In extended programming, the sampler offers an additional distri-
bution feature, time switching. This feature determines when the
sampler goes to the next bottle or bottle set, and may be used with
time-paced or flow-paced sample programs. Time switching distri-
bution occurs at regular intervals (as programmed in screen
16 in
the margin). The switch times are relative to the programmed
“FIRST SWITCH TIME” (screen
17 ).
Switch times occur regardless of the state of the sampler. Be aware
that the sampler may leave empty bottles if it becomes disabled.
Pause and resumes are an exception; the sampler will not switch
bottles during a pause if the current bottle is empty.
If the program settings instruct the sampler to take a sample at the
start time, the sampler also draws a sample at the switch time.
When this occurs, the pacing will also be reset at the switch time.
Time overrides can also be used with flow-paced programs that do
not take a sample at start. These programs will place a sample in the
current bottle if it is empty at the switch time, and then move to the
next bottle/set. This sample is called a
time override sample and en-
sures that at least one sample is taken into each bottle. Pacing inter-
vals are reset at every switch time.
When you use the time switching feature, the volume in each bottle
or bottle set may vary. Sample volumes that would exceed the bot-
tle capacity are not taken and a “PROBABLE OVERFILL” message
is logged.
Continuous Sampling
Sample programs can be run indefinitely by selecting “YES” at the
“RUN CONTINUOUSLY?” screen. Continuous sampling resets the
distribution when the distribution sequence is complete. That is,
when the last bottle/set is reached, the next bottle/set is the first
bottle/set. All pacing modes except RANDOM are supported.
When running a program continuously, the bottles must be serviced
at regular intervals to prevent overfilling the bottles. The sampler
assumes that the next bottle/set is empty and ready to receive sam-
ples. If you are using this feature with two-part programming, keep
in mind that the parts will most likely reset at different intervals.
Time Switched Distribution
14
2 BOTTLES PER
SAMPLE EVENT (1-max)
• Enter the number of bottles
that should receive samples at
each sample event.
15
SWITCH BOTTLES ON:
NUMBER OF SAMPLES
TIME
• Select TIME.
16
SWITCH BOTTLES EVERY
__ HOURS, __ MINUTES
• Enter the time between bottle
switches.
17
FIRST SWITCH TIME
AT: __:__
• Enter the first bottle switch
time.