Lindab UltraLink FTMU, Техническая информация

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Lindab reserves the right to make changes without prior notice
2021-11-02
Lindab reserves the right to make changes without prior notice
2021-11-02
UltraLink
®
Monitor FTMU
lindab | technical information
Planning
The longer distance to disturbance, i.e. the longer straight duct before the FTMU, the higher the measurement accuracy
will be. However this is not the only factor which affects the accuracy of the measurement. The rotation of the FTMU
and hence the positioning of the first flow sensor has an impact on the uncertainty of the measurement. It is not
recommended to mount the FTMU so that the first flow sensor (*) is placed on an outer radius of a fitting.
For example: in the case of the bend in the table below, by rotating the FTMU to position the first flow sensor according
to the first picture (with the first flow sensor on the inner radius of the bend), the FTMU can be placed at the distance
of two duct diameters from the disturbance to achieve 5 % uncertainty. Positioning the FTMU according to the second
picture (with the first sensor on the outer radius of the bend), the FTMU must be mounted five duct diameters from the
disturbance to achieve the same level of uncertainty.
Other obstructions in the duct system such as axial fans, silencer baffels or cleaning hatches etc. are not allowed before
the UltraLink (in the direction of the flow). If a cleaning hatch is required, it must be placed after the UltraLink (in the direc-
tion of the flow). The reason is that these cause turbulences, which can result in errors in flow measurements.
Disturbance * Placement of first flow sensor
Measurement uncertainty
± % or X l/s depending wich
is the greatest of percentage
or the absolute value for the
specific product size, see
table on page 16.
a
2-4·Ød >4-5·Ød >5·Ød
Bend
a
Ød
*
Inner radius
(Best position)
5 5 5
Bend
a
Ød
*
Outer radius
(Not recommended)
20 10 5
Bend
a
Ød
*
a
Ød
*
Side
10 5 5