C
HAPTER
4
O
PERATION AND
U
SE
P
AGE
31
►
flush time
The pre-analysis flush time is programmed using the left hand rotary switch
“Flush
time“. The range is from 5 seconds to 30 minutes.
Calculate the flush time according to the length of the water supply pipe in order
to ensure an analysis of a fresh sample.
→ For example:
a 5 meter long pipe (6 x 4) with an inner diameter of 4 mm has a volume of
approximately 63 ml and, depending on the pressure, will be flushed in
approximately 4 seconds.
rules of thumb:
→ one meter of a pipe with inner Ø 4mm contains approx. 13 ml water
→ doubling the diameter results in a fourfold volume (Ø 8 mm ca. 50 ml/m)
→ The rate of flow is influenced by the internal diameter of the inlet valve and
the water pressure.
The operating conditions will vary according to the location of the plant. They are
affected by the size of the supply pipes and the pressure reductions due to heavy
demand from other users, etc.
Measure the amount of flushed water at the current settings and then compare this
with the theoretical amount that you have calculated. Set the flush time accordingly
to ensure that a fresh sample is taken.
We recommend a minimum flush time of 20 seconds.
►
delay time
The time delay prior to taking a sample is programmed using the right hand rotary
switch
“delay time“. The range is from 0 seconds to 30 minutes.
Choose the delay time to ensure that no hot water is introduced into the
measuring-chamber.
→ When monitoring condensate, it is necessary to cool the sample to below
40°C. If there is a long time interval between analyses, it makes no sense
to keep the condensate permanently cool. A cool water valve can be
opened when a sample is required. Only when the sample temperature is
under 40°C should the inlet valve to the analyser be opened.
Pos
time
Pos
time
Pos
time
Pos
time
0
5 s
4
90 s
8
10 m
C
18 m
1
10 s
5
2 m
9
12 m
D
20 m
2
20 s
6
4 m
A
14 m
E
25 m
3
50 s
7
8 m
B
16 m
F
30 m
Pos
time
Pos
time
Pos
time
Pos
time
0
0 m
4
4 m
8
8 m
C
18 m
1
1 m
5
5 m
9
9 m
D
20 m
2
2 m
6
6 m
A
10 m
E
25 m
3
3 m
7
7 m
B
12 m
F
30 m
NOTE
NOTE
NOTE
