KAPTOR
MINI
–
User Manual
–
V0.1 - pg.50
12.1.2.2
TTFM sensor
The TTFM (Transit Time Flow Meter) sensor allows to carry out the bidirectional measurement of the flow
rate in full pipes, using ultrasound transit time technology. The measurement is made by using two
transducers positioned on the external pipe surface (non-invasive technique) in a specific geometric
configuration and distance. This system allows to have no pressure drop and no interruption of the service
since the installation does not foresee any intervention on the pipe.
For a correct measurement it is essential to know accurately the pipe features in terms of dimensions and
materials as well as the type of liquid that flows inside it. In fact, depending on the materials and the
liquid, the different sound propagation speeds are determined, in order to allow a precise calculation of
the flow rate.
TTFM sensor configuration is possible only if it is connected to
KAPTOR
MINI
.
Before setup, save and load the type of RS485 sensor, otherwise the device will not be able
to communicate with TTFM.
Entering settings, EasySetup will automatically read the configuration of TTFM sensor.
Transducer distance
: it is the value of the mounting
distance of the transducers, in millimeters. The value
cannot be changed and is related to the last configuration
read by the TTFM. By changing one or more parameters,
this value is updated only after saving and loading on the
instrument.
Circumference, external diameter, pipe thickness, internal
diameter
: these are the dimensions, in millimeters, of the
pipe. By updating one of them, the others are automatically
updated.
Pipe material
: it is possible to choose among a standard list.
Sound speed in pipe
: it is the speed of propagation of sound
into the pipe material. It must be specified only if the
material is not among the predefined ones.
Coating material
: it identifies the pipe coating, if any. It is
possible to choose among “no
inner coating
” and a list of
standard liners.
Sound speed in coating
: it is the speed of propagation of
sound into the pipe coating. It has to be specified only if the
material is not included among the standard ones.
Coating thickness
: it is the thickness of the coating, in
millimeters.
