Endress+Hauser Liquistation CSF48 - Page 34

Programming Liquistation CSF48
34
The following table explains the various types of sampling using specific examples.
Type of sampling Example Info
Time-paced • Sampling interval: 5 min
• Sampling volume: 50 ml
•Bottle change mode: 2 h
With this setting, a 50 ml sample is taken every
5 minutes. 12 samples are thus taken every
hour. Each bottle is filled over a period of 2
hours. This results in a total sampling volume of
24 samples per bottles x 50 ml = 1200 ml.
This type of sampling remains constant over
time and does not take changes in flow or pollu-
ting load into account. It is possible to take a
representative sample if the intervals are brief
(e.g. 5 min).
Flow-paced Controlled via current input
• Signal: 0 to 20 mA = 0 to 600 m³/h
• Sampling volume: 50 ml
• Sampling interval: 20 m³
•Bottle change mode: 2 h
If 20 mA = 600 m³/h, a sample is taken every 2
minutes (smallest sampling interval with maxi-
mum flow). The total number of samples
amounts to 60 samples per bottle. With a flow
of 300 m³/h, a sample is taken every 4 minutes.
Controlled via binary input
• Signal pulse: 5 m³
• Sampling volume: 50 ml
• Sampling interval: 20 m³
•Bottle change mode: 2 h
The pulses are scaled at the flowmeter. By mul-
tiplying the pulses at the sampling interval, the
shortest sampling interval at the maximum
pulse frequency can be set.
Example: Given a maximum flow of 600 m³/h,
the pulse frequency at 5 m³ is 120 pulses/h or 2
pulses/min. With a sampling interval of 20 m³,
sampling takes place after 4 pulses = 2 minutes.
• The current inputs can be configured for the
current range of 0 to 20 mA or 4 to 20 mA.
• The binary inputs require power (24 V DC)
for floating contacts.
In the case of flow-paced sampling, the samp-
ling interval is calculated on the basis of the
volume flow. The same sampling volume is take
at variable intervals.
Advantage:
Good, representative results in the event of
minor fluctuations in flow.
Disadvantage:
Longer intervals when the level of water is low
mean that malfunctions cannot be detected.