Pag. 2 of 52
- Working principle
Where:
= sonic section angle
M = sonic section length
D = pipe internal diameter
T1 = sound transit time from the upstream transducer to the transducer downstream
T2 = sound transit time from the downstream transducer to the transducer upstream
∆
T = Tup-Tdown
1. WORKING PRINCIPLE
The meter is designed to measure the fluid velocity inside a pipe.
The clamp-on transducers models allow an easy installation.
The transit time flow meter uses two ultrasonic transducers that function as transmitters and receivers.
They are installed externally to the pipe at a specific distance from each other. They can be installed at
V
mode (2
sonic section), at
W
mode (4 sonic section) or at
Z
mode (1 sonic section). The installation method choice depends
on the pipe and the fluid characteristics. The
instrument
measures the transit time via the two transducers that
alternatively transmit and receive a sound pulses sequence. The difference in the measured transit time is directly
related to the fluid velocity in the pipe, as shown in figure 1
Compact system for conductive and
non-conductive fluids, even with the
suspended material presence (<10g/l; <Ø1mm)
Measuring ranges from <0,2m
3
/h to >30000m
3
/h
A p p l i c a b l e t o v a r i o u s p i p e s m a t e -
r i a l s ( e g . S S 3 1 6 , c o p p e r, p l a s t i c ,
etc.), with or without an inner lining
Power supply 85 ÷ 265Vac or 10÷30Vdc
The
instrument
is composed by a digital converter and two clamp-on or insertion type ultrasonic transducers.
The instrument calculates the instantaneous flow rate value by measuring the flight time difference of the ultrasonic
pulses.
Fig. 1
