Properly locating the 2551 and 2552 Magmeter into the Flow Stream
The Signet 2551 and 2552 Magmeters from Georg Fischer are successful products that work in the difficult applications presented by industries around the world. To make the most of this product, it is important to understand the fundamental technology and the basic installation requirements.
Fundamental Technology: Faraday’s Law 1. When a conductive fluid passes through a magnetic field, a voltage (E) is generated.
This is Faraday’s Law. (Signet requires a minimum conductivity of 20 µS for practical reasons.)
2. When power (V) is applied to the Magmeter, a pulsing current through the sensor coil develops a pulsing magnetic field that surrounds the tip of the sensor.
3. The voltage produced by the conductive fluid passing through the magnetic field is proportional to the flow rate. The Magmeter measures this voltage.
4. The circuitry inside the Magmeter converts the voltage into a linear velocity, and then into a pulse signal or a 4-20 mA signal, 10 times per second.
5. As long as a conductive fluid passes through the magnetic field, a pulse output will be developed by the sensor and transmitted to a Signet transmitter (or 4-20 mA output). If the piping system contains significant amounts of air, stable readings may be difficult to achieve because air pockets passing the sensor will interrupt the process.
Basic Installation Requirements
One of the most important installation considerations for an insertion magmeter is selecting a pipe location that is not subjected to entrained air across the electrodes.
Figure 1:
Wherever possible, design the piping system to eliminate entrained air. Vertical pipe runs are ideal.
Figure 2:
When installing the Magmeter in horizontal pipe runs, install the sensor at an angle, greater than the 11:00 or 2:00 position, around the pipe.
Avoid the 12:00 position where air bubbles will accumulate, and the 6:00 position where sediments may cover the electrodes.
The Signet Advantage
In many installations, it is almost impossible to achieve 100% air-free flow, especially if the magmeter is installed into an existing piping system. When the basics installation requirements are just not feasible, Signet has an advantage.
• Signet 2551 and 2552 Magmeters feature a signal processing design that is now in the 5th generation. Time and experience have resulted in a sophisticated flow meter that makes erratic performance a rare occurrence.
• When the application challenges the limits of the technology, Signet Magmeters have another tool that can be employed to adapt the meter to suit the unique applications that our customers must address.
• The Signet 3-0250 USB-to-Digital Configuration/Diagnostic Tool can be used to modify all of the critical parameters in the magmeter.
Remember: Good installation practices and Signet’s design excellence guarantee application success.
