Magmeter flow meter guide covering working principle, selection, specs, installation advantages, and Sino-Inst electromagnetic solutions.
What is a Magmeter Flow Meter?
Magmeter Flow Meters are also called Electromagnetic flow meters or magnetic meters. Magmeter Flow Meter is a type of volumetric flow meter. It is mainly used to measure high-precision flow measurements of various conductive fluids. Such as water-based liquids, mixed media such as mud and sludge can also be measured.
Magmeter Flow Meters are based on Faraday’s Law of Electromagnetic Induction. We Sino-Inst offer a range of full-bore and insertion electromagnetic meters. Covering pipe diameters from DN6 to DN3000. Accuracy can reach 0.5%.
Choose the Suitable Magmeter Flow Meters
I’ve found that when it comes to reliability and long-term value, the magmeter flow meter is often the best investment for any liquid-based operation. It’s a versatile magnetic flow meter that eliminates the common failure points found in traditional mechanical meters.
Key Advantages of Using a Magmeter Flow Meter
- Zero Maintenance Headaches: Because there are no moving parts inside the sensor, there’s nothing to wear out, jam, or break. This translates to a massive reduction in downtime and service costs.
- Obstructionless Design: This is a full bore magmeter. The internal flow path is completely clear, meaning there is no pressure drop. Your pumps don’t have to work harder to push fluid through the meter.
- High Accuracy Levels: For processes where precision is non-negotiable, these units deliver. Most of our flow meter accuracy specifications hit between ±0.2% and ±0.5% of the flow rate.
- Immune to Fluid Variables: As a specialized conductive liquid flow sensor, it isn’t affected by changes in temperature, pressure, or viscosity. If your fluid thickness changes mid-process, the reading stays true.
- Bidirectional Flow: An inline electromagnetic flowmeter can measure flow in both directions. This is a huge plus for complex piping systems where backflow or directional changes occur.
First, let us look at the structure of the magmeter.
The structure of electromagnetic flowmeter is mainly composed of magnetic circuit system, measuring catheter, electrode, shell, lining and converter.
The electromagnetic flowmeter is made according to Faraday’s law of electromagnetic induction. It is used to measure the volume flow of conductive liquid.
Faraday’s law of induction (referring to the induction of an electric potential inside the conductor when the conductor passes through a magnetic field) is the basic principle of electromagnetic flowmeter measurement.
This measurement principle can be applied to conductive fluids.
The fluid flows into a pipe whose magnetic field is perpendicular to the direction of the fluid, and the electric potential induced in the fluid can be measured using two symmetrically arranged electrodes.
The signal voltage UE is proportional to the magnetic induction intensity B, the electrode spacing D and the average fluid velocity v.
Because the magnetic induction intensity B and the electrode spacing D are constant. Therefore, the signal voltage UE is proportional to the average flow velocity v.
The equation used to calculate the volume flow rate shows that the signal voltage UE is linearly proportional to the volume flow rate.
The sensed signal voltage is converted into the graduation in the converter, analog and digital output signals.
Our magmeter flow meter solutions are engineered to thrive where other technologies fail. Because they have no moving parts and rely on conductivity, they are the go-to choice for several demanding global industries.
Wastewater Flow Measurement and Management
We primarily deploy these meters in municipal and industrial water systems. Since the inline electromagnetic flowmeter features an unobstructed bore, it handles raw sewage, influent, and effluent without clogging.
- Leak Detection: High accuracy helps monitor distribution networks.
- Effluent Monitoring: Ensures compliance with environmental discharge regulations.
- Chemical Dosing: Precise control for water treatment chemicals.
Handling Corrosive Chemicals and Acids
For chemical processing, we recommend a chemical compatible flowmeter equipped with specialized liners like PTFE or PFA. These materials are immune to the aggressive nature of acids and caustics that would otherwise destroy mechanical meters.
- Safety: No leak paths through moving seals.
- Reliability: Maintains flow meter accuracy specifications even in highly volatile environments.
- Versatility: Works with a wide range of conductive process fluids.
Hygienic Flow for Food and Beverage
In the food and beverage sector, hygiene is everything. Our magmeter flow meter designs meet strict sanitary standards, featuring stainless steel housings and food-grade liners.
- Clean-in-Place (CIP): Can withstand high-temperature steam and chemical cleaning without removal.
- Zero Contamination: No internal crevices where bacteria can grow.
- Applications: Ideal for milk, juice, beer, and liquid chocolate.
Measuring Abrasive Slurries in Mining and Paper Mills
A slurry flow meter needs to be tough. We use heavy-duty rubber or ceramic liners to protect the device from the constant bombardment of solids in mining and pulp applications.
| Industry | Typical Fluid | Key Requirement |
|---|---|---|
| Mining | Ore Slurries | Abrasion Resistance |
| Pulp & Paper | Paper Stock/Black Liquor | High Solids Handling |
| Chemical | Sulfuric Acid | Chemical Inertness |
| Water | Potable Water | Low Pressure Drop |
Extended Reading: Guide: Magnetic Flowmeter Installation
Magmeter liner selection should be selected according to the corrosiveness, abrasiveness and temperature of the measured medium.
- Hard/soft rubber is resistant to general weak acid and alkali corrosion. Temperature resistance is 65℃. Soft rubber has abrasion resistance.
- Polytetrafluoroethylene (PTFE) is almost resistant to strong acid and alkali corrosion except hot phosphoric acid. The temperature of the medium can reach 130℃. But it is not resistant to wear.
- Polyurethane rubber has good wear resistance. But it is not resistant to acid and alkali corrosion. Temperature resistance is also poor. The medium temperature is less than 65°C.
| Liner Materials | Functions | Applications |
| Hard rubber | 1. It is resistant to hydrochloric acid, acetic acid, oxalic acid, ammonia, phosphoric acid and 50% sulfuric acid, sodium hydroxide, and potassium hydroxide at room temperature. 2. Avoid strong oxidants. | 1, below 70℃ 2. General acid, alkali, and salt solutions. |
| Soft rubber | 1. It has good elasticity and good wear resistance; 2. It is resistant to the corrosion of general low-concentration acids, alkalis, and salt media, and is not resistant to the corrosion of oxidizing media. | 1. Below 70℃; 2. Measure general water, sewage, mud, ore slurry |
| Polytetrafluoroethylene (PTFE) Modified polytetrafluoroethylene (PFA) | 1. The material with the most stable chemical properties in plastics. It can withstand boiling hydrochloric acid, sulfuric acid, nitric acid and aqua regia, as well as strong alkalis and various organic solvents; 2. Poor abrasion resistance and adhesion. | 1.-40℃~+130℃C(PTFE), -40℃~+160℃(PFA); 2. Strong corrosive media such as acid and alkali; 3. Sanitary media. |
| PO | 1. It can withstand hydrochloric acid, acetic acid, oxalic acid, ammonia, phosphoric acid, sulfuric acid, sodium hydroxide, and potassium hydroxide at room temperature. 2. It can withstand concentrated alkali and various organic solvents. | 1. Below 70℃; 2. General acid, alkali, and salt solutions; 3. General water, sewage, mud, mineral slurry. |
| Ceramics | Wear resistance, high temperature resistance, corrosion resistance | Below 200℃ |
Getting your magmeter flow meter installed correctly is the difference between pinpoint accuracy and total frustration. I’ve seen many industrial flow metering setups fail simply because basic layout rules were ignored. To get the best ROI from your full bore magmeter, follow these hard-and-fast rules.
Straight Run Requirements
For a stable flow profile, you need straight pipe sections before and after the meter. Turbulence from valves or elbows will throw off your readings.
- Upstream: Maintain at least 5x the pipe diameter (5D) of straight pipe before the meter.
- Downstream: Maintain at least 2x the pipe diameter (2D) of straight pipe after the meter.
- Pro Tip: If you have a high-disturbance element like a pump nearby, I recommend increasing the upstream run to 10D.
Proper Grounding and Electrode Orientation
Since an electromagnetic flow meter measures tiny microvolt signals, electrical noise is the enemy.
- Grounding: You must ensure the fluid and the sensor are at the same electrical potential. Use grounding rings if you are installing in plastic or lined pipes.
- Electrode Alignment: Always install the meter so the electrode axis is horizontal. If electrodes are vertical, air bubbles at the top or sediment at the bottom will break the circuit and cause signal loss.
Ensuring Full Pipe Conditions
A magmeter flow meter cannot measure accurately if the pipe is only half-full. The sensor must be completely submerged in the conductive liquid to function.
| Installation Scenario | Recommended Practice |
|---|---|
| Vertical Pipes | Always flow upward. This ensures the pipe stays full and prevents air pockets. |
| Horizontal Pipes | Avoid the highest point of the system where air collects. |
| Downhill Runs | Install a “U-trap” or an orifice plate downstream to create backpressure and keep the meter full. |
Avoiding Air Pockets and Sediment
Air bubbles are the most common cause of “jumpy” readings in wastewater flow measurement. I suggest avoiding installations immediately after a pump intake or at the very top of a pipe header. If your application involves slurry flow meter usage, high-velocity flow is your friend to prevent solids from settling on the electrodes.
Magnetic flowmeter is a widely used flow measuring instrument. How should we calibrate it?
Let’s take a look at the calibration method of electromagnetic flowmeter:
- Determine the corresponding water pump according to the pipe diameter and flow rate of the verification test;
- After the flowmeter is correctly installed and connected, it should be energized and preheated for about 30 minutes in accordance with the requirements of the verification regulations;
- If the high-level tank water source is used, check whether the overflow signal of the stabilized water tower appears. Before the formal test, use the verification medium to circulate in the pipeline system for a certain period of time. At the same time, check whether there is any leakage in the sealing parts of the pipeline;
- The verification medium should be filled with the electromagnetic flowmeter sensor before the formal verification. Then the downstream valve should be closed to adjust the zero position;
- At the beginning of the verification, open the valve at the front of the pipeline and slowly open the valve behind the electromagnetic flowmeter to adjust the flow at the verification point.
- During the calibration process, the flow stability of each flow point should be within 1% to 2%-flow method. The total amount law can be within 5%.
- The temperature change of the verification medium should not exceed 1℃ when the verification process of a flow point is completed. It should not exceed 5℃ when the entire verification process is completed.
- There must be a sufficiently high pressure downstream of the electromagnetic flowmeter to be checked to ensure that no flashing and cavitation occur in the flow pipeline;
- After the test, close the valve at the front end of the test pipeline. Then stop the pump to avoid emptying the voltage stabilization facility. At the same time, the remaining verification medium in the test pipeline must be vented and the control system and the air compressor must be closed.
Extended reading:
What is the K-factor in a flow meter?
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Magnetic flow meter manufacturers
Sino-Inst is one of the reliable Magnetic flow meter manufacturers and suppliers in China. Magnetic flow meters are applied for wastewater flow rate measurement.
Sino-Inst offers over 20 Magnetic flow meters at the Best Price. A wide variety of Magmeters options are available to you, such as free samples and paid samples.
About 40% of these are magnetic flow meters, 30% are Insertion Magnetic Flow Meter, and 30% are sanitary flow meters. Magmeters’ products are most popular in North America, the Middle East, and Eastern Europe.
You can ensure product safety by selecting from a certified supplier with ISO9001 and ISO14001 certifications.
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Wu Peng, born in 1980, is a highly respected and accomplished male engineer with extensive experience in the field of automation. With over 20 years of industry experience, Wu has made significant contributions to both academia and engineering projects.
Throughout his career, Wu Peng has participated in numerous national and international engineering projects. Some of his most notable projects include the development of an intelligent control system for oil refineries, the design of a cutting-edge distributed control system for petrochemical plants, and the optimization of control algorithms for natural gas pipelines.