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KATflow 150
2 Introduction
2 Introduction
Clamp-on transittime flowmeter
The KATflow 150 is an ultrasonic flowmeter utilising clamp-on sensors for the
measurement of liquids in full closed pipes. Flow measurements can be undertaken without interrupting of the process or interfering with the integrity of the
pipeline. The clamp-on sensors are simply attached to the outside of pipes. The
KATflow 150 uses ultrasonic signals for the measurement of the flow, employing
the so-called transit-time method.
Illustration 1: Clamp-on ultrasonic flowmeter configuration
Measuring principle
Ultrasonic signals are emitted by a first transducer installed on one side of a pipe,
reflected on the opposite side and received by a second transducer. These signals
are emitted alternatively in the direction of flow and against it. Because the medium
in which the signals propagate is flowing, the transit time of the sound signals
propagating in the direction of flow is shorter than the transit time of the signal
propagating against the direction of flow. The transit-time difference ∆T is measured and allows the determination of the average flow velocity along the path of
acoustic propagation. A profile correction is then performed to obtain the average
flow velocity over the cross-sectional area of the pipe, which is proportional to the
volumetric flow rate.
Illustration 2: Transit-time measuring principle
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