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www.hoentzsch.com U426_flowtherm Ex_B_e_171206
5.3.13
TA - Measurement settings
Menu -> Settings -> Sensor -> TA Input -> Measurement settings
The task to be carried out determines the parameter, section and profile factor to be set.
5.3.13.1
Section
Setting the measuring section for measuring in pipelines for flow rate display:
Selection:
Circular
= for pipes with circular section
di/mm: enter the ID in mm
Rectangular = for pipes with rectangular section
a/mm: enter the inner surface a in mm
b/mm: enter the inner surface b in mm
5.3.13.2
Profile factor
The profile factor PF specifies the ratio of mean flow velocity in the measuring section and the flow velocity
measured from the sensor. Requirements are: centric sensor positioning,
non-rotational inlet flow
and
adequate dimensioned input/output sections. (See also Documents U232 and U234)
Following profile factors are to be set for thermal flow sensors TA10 subject to the pipe diameter:
Pipe ID
in mm
PF for thermal
sensors TA10
25
0,725
27,2
0,740
35,9
0,790
40
0,810
41,8
0,820
50
0,840
...
0,840
For measuring in larger free jet as well as larger ducts or measuring tubes with setting PF = 1.000 the
local/punctual velocity will be displayed.
With
TABLE a profile factor subject to the set diameter of the measuring surface (5.3.13.1) is rec-
ommended. This value can be verified or also amended before saving. With rectangular selected as meas-
uring surface, the surface is converted to circular for the proposed value and this value is approximate.
PF = 1.000 must always be set for TADi.. measuring tubes calibrated with pairs of values!
5.3.13.3
Pressure
B Working pressure in hPa as absolute pressure for zero correction.
5.3.13.4
Damping
The damping rate set here affects the measured value display, if TA is selected as sensor in the display
settings (5.3.19.1).
Damping/s: enter the damping time of 01 to 99 seconds
Example 10 seconds: after every second the arithmetical average of the last 10 seconds is displayed.
