Operation Liquistation CSF34
78 Endress+Hauser
10.3.1 Overview of the possible program types
The graphic below explains the various ways sampling can be controlled on the basis of a
flow curve:
A0014045
66 Sampling control
Q Flow
t Time
a. Flow curve
b. Time-proportional sampling (CTCV)
A constant sample volume (e.g. 50 ml) is taken at regular
intervals (e.g. every 5 min).
c. Volume-proportional sampling (VTCV)
A constant sample volume is taken at variable intervals
(depending on the inflow volume).
d. Flow-proportional sampling (CTVV)
A variable sample volume (the sample volume depends on the
flow rate) is taken at regular intervals (e.g. every 10 min).
e. Event-controlled sampling
Sampling is triggered by an event (e.g. pH limit value). Sampling
can be time-paced, volume-paced or flow-paced, or single
samples can be taken.