Instruction Manual VisGuard 2 E xtractive
Design and function
16
14265E/1
4.2
Functional description of the most important elements
4.2.1
Valve unit for multiple sampling
Figure
2
: Principle of continuous sample taking
a
Measurement of sample “P1”
b
Measurement of sample “P2”
Continuous sample transport is the most reliable concept for multiple sampling. Here, the
samples from all measuring points are continuously suctioned in by a valve unit with two or
more channels. Only the sample that is to be measured at the specific time is released by the
corresponding valve and allowed to enter the measuring instrument. Section 5.3.2
The advantage of this system is that all measuring points are constantly in operation and no
static sample flows can arise. This means that almost no deposits build up in the lines, with
peaks in measuring values or blockages virtually ruled out.
The samples are switched via a control unit, which is also used to allocate the measuring va-
lue to the correct sampling point.
P1
P2
a
b
P
P1
P2
P
