Liquistation CSF48 Programming
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Time/flow-paced
(only possible with
peristaltic pump)
Controlled via current input
• Signal: 0 to 20 mA
• Sampling interval: 10 min
• Sampling volume: variable
The maximum sampling volume is defined at
the maximum flow rate.
Example: The maximum flow rate at 20 mA at
the current input is 160 l/s, and the maximum
sampling volume is 200 ml. When transferring
samples into a 30l mixed sample container, 144
samples are taken per day with a maximum
sampling volume of 28.8 l. With a flow rate of
80 l/s, a sampling volume of only 100 ml would
be grabbed, and a sampling volume of 50 ml
would be grabbed at a flow rate of 40 l/s.
The sampling volume is always calculated based
on the flow.
Controlled via binary input
• Binary input (pulse per flow unit)
• Sampling interval: 10 min
• Sampling volume: variable
The sampling volume is defined for a flow pulse,
e.g.: 1 pulse is 20 ml. For instance, if 5 flow pul-
ses are counted between the sampling intervals,
this results in a sampling volume of 5 x 20 =
100 ml, and a volume of 8 x 20 = 160 ml for 8
pulses.
If a binary input is used for time/flow-paced
sampling, the sampling volume is calculated per
sample as a percentage of the specified samp-
ling volume.
Samples are taken at set intervals with a varia-
ble sampling volume. The sampling volume is
calculated from the flow rate. More volume is
grabbed when the flow is high than when it is
low. Since the flow normally fluctuates and the
maximum flow is only rarely a constant variable,
the sampling volume transferred to the contai-
ner will depend on the daily average.
Advantage:
Very good, representative sampling given large
fluctuations in the flow and constant time inter-
vals.
Disadvantage:
Too little sampling volume is made available for
analysis when the flow is low.
Advantage with current input:
For the sampling interval, either the current
flow rate or the average value between the last
and current flow rate is used to calculate the
exact sampling volume (depending on the pre-
setting).
Disadvantage with binary input:
For the sampling interval, the pulses counted
since the last sampling are multiplied by a
volume. If this is too high - e.g. 100 ml - the
composition of the sample is not representative
for analysis.
Event Event-based sampling is controlled via the cur-
rent input, binary input and/or sensor input.
The subprogram created waits to be activated by
an event that can consist of up to 3 individual
events. Every possible condition can be created
using logical "and" / "or" links. For example, the
information from a flowmeter connected to the
current input can be linked to a rain gage and a
pH sensor signal connected to the binary input.
An event is defined as limit value violation
(exceeded or undershot), range monitoring
within or outside a range, or a rate of change.
Users can decide whether additional sampling is
started when the event starts and/or ends. For
the duration of the event, users can choose from
time-paced, flow-paced or time/flow-paced
sampling, or can take single samples, use a sam-
pling table or the external control system.
The sampler waits for an event. This event takes
place via internal sensor signal processing or via
devices connected externally. As bottle assign-
ment is possible when using several bottles,
events can be assigned to individual bottles. A
maximum of 24 subprograms can be started
simultaneously and assigned to individual bott-
les.
Type of sampling Example Info
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