FISCHER PRO-LINE DE90 Operating Manual page 76

5 | Operation
76
Square-root approximation of the characteristic curve
If the filter characteristic curve is strongly curved, a more exact approximation
may be necessary. In this case, the
to the 'Square-root' value.
The software then calculates a square root characteristic from the other para-
meters.
Q
min
[Pa] Δp
300
250
200
150
100
50
1 2 3 4 5
Fig. 108: Square-root approximation of the filter characteristic curve
∆p correction value
The
linear characteristic curve so that the deviation from the real filter characteristic
curve is minimized over the entire operating range.
[%] [Pa] Δp
300
250
200
Operating point
150
100
100%
50
0%
1 2
Fig. 109: Correction value square-root filter characteristic curve
Displ.range C3 start
With the parameters
end
the display characteristic curve can be spread appropriately. Since the
limit curve for the contaminated filter is now fixed, the degree of contamination
of the filter can be determined dynamically for any operating point.
FISCHER Mess- und Regeltechnik GmbH
Approximation
Q
max
Δp
max (soiled)
Δp
max (clean)
6 7 8 9 10 [1000 m
parameter can be used to set an offset for the
Q
Q
max
min
Δp
max (soiled)
Offset
3 4 5 6 7 8 9 10 [1000 m
Volume flow
parameter can be set
filter characteristic curve
soiled filter
filter characteristic curve
clean filter
square root approximation
Q
3
/h]
filter characteristic curve
soiled filter
corrected filter characteristic
curve soiled filter
soiled filter
clean filter
display range
Q
3
/h]
Displ.range C3
and
BA_EN_DE90