Misurazione del volume basata sul principio induttivo
Il principio di misurazione del flussimetro magnetico induttivo si basa sulla legge di Faraday sull’induzione elettromagnetica. Le bobine in aria integrate nel tubo di misurazione generano un campo magnetico comune (B) ortogonale alla direzione del flusso. I portatori di carica di un liquido conduttore (Q) vengono deviati al momento dell’attraversamento del campo magnetico generando una tensione elettrica (U). La tensione è proporzionale alla velocità di flusso media e viene registrata dai due elettrodi. Ovvero, maggiore è la velocità di flusso, maggiore sarà la tensione indotta. Il segnale di tensione viene convertito in volume di flusso dal sistema elettronico integrato del trasduttore di misura in base al diametro nominale del tubo.
Structure of the electromagnetic flow meters from Baumer
Electromagnetic flow meters from Baumer consist of a transducer (PF75H/S optionally with a display) and the sensor. The sensor is directly installed in the process, i.e., in the pipe (inline), and measures the induced voltage that is created by the conductive medium while the medium flows through the measurement pipe. The sensor is available for different pipe dimensions and applications.
1) Transducer
2) Optional display
3) Sensor
2) Optional display
3) Sensor
Display
Key parameters and the menu functions can be shown and configured in the CombiView display of the flow sensor.
How is the display structured?
The display is divided into 3 sections:
1) Status bar
The status bar shows pictograms for alarm and error messages as well as the status of the DFON relays.
2) Main section
Depending on the selected display layout, the following measured values are shown in the main section:
Depending on the selected display layout, the following measured values are shown in the extra bar:
For more information about the display menu navigation and the available display layouts, see the operating manual of the PF75H/S sensor variants.
1) Status bar
The status bar shows pictograms for alarm and error messages as well as the status of the DFON relays.
2) Main section
Depending on the selected display layout, the following measured values are shown in the main section:
- Flow rate
- Positive partial counter
- Negative partial counter
- Net partial counter
- Positive overall counter
- Negative overall counter
- Net overall counter
Depending on the selected display layout, the following measured values are shown in the extra bar:
- Label or number tag
- Units of the measured values
- Graphical display of the flow rate
For more information about the display menu navigation and the available display layouts, see the operating manual of the PF75H/S sensor variants.
Wide selection of measurement pipe linings
The electromagnetic flow sensors from Baumer offer a wide range of measurement pipe linings for every medium. The correct selection of the optimum material depends on the medium, proportion of solids in the medium, process pressure, and process temperature.
Table with recommended materials:
Table with recommended materials:
Selecting the appropriate flow meter
The choice of the appropriate flow meter depends not only on the measurement pipe lining but also essentially on the nominal width of the measurement pipe, i.e., the sensor. The nominal width is generally determined by the existing pipeline. With the help of the alignment chart below, you can carry out a control calculation based on the predominant flow velocity of the system.
Deviating values
If there are deviations between the calculated nominal width of the flow sensor and the specified pipe diameter, then the value of the sensor is usually lower. If the constriction angle is less than 8°, it can be adjusted with conical flange adapter pieces. It is essential to take the pressure loss occurring in the system into account. The pressure loss can be found in the overview below at the intersection of the diameter ratio d/D and the flow velocity on the y axis.
Nominal flow:
