flowIQ® 3100 TECHNICAL DESCRIPTION
Kamstrup
A/S • Technical Description • 5512
-1242_N1
_GB •
10.2019
25
11.2
Temperature measurement
flowIQ® 3100 measures water
*)
and ambient/meter temperature
- also see section
The following accuracies apply to temperature data:
Water temperature:
0 - 20 °C ± 1 °C
20 - 30 °C ± 2.5 °C
> 30 °C
–
No valid measurement
Ambient/meter temperature: -5 - 55 °C ± 1 °C (temperature in meter housing)
*)
Applies only the smallest meter sizes - 1.6, 2.5 and 4.0 m
3
/h
12
Measuring principle
12.1
Ultrasound with piezo ceramics
Flow sensor manufacturers have been working on alternative techniques to replace the mechanical principle.
Research and development at Kamstrup has proven that ultrasonic measuring is the most viable solution. Based on
microprocessor technology and piezo ceramics, ultrasonic measuring is not only accurate but also reliable.
12.2
Principles
Ultrasound signals are sent in the measuring tube from one transducer to another, via reflectors.
The thickness of a piezo ceramic element changes when exposed to an electric field (voltage). When the element
is mechanically affected, a corresponding electric charge is generated. Therefore, the piezo ceramic element can
function as both sender and receiver.
Principle of ultrasound signal path
Within ultrasonic flow measuring there are two main principles: the transit time method and the Doppler method.
The Doppler method is based on the frequency change which occurs when sound is reflected by a moving particle.
This is very similar to the effect you experience when a car drives by. The sound (the frequency) decreases when
the car passes by.