Company Profile

Magmeters & Magnetic Sinks: Reliable Inline Velocity Monitors for Conductive Media

Quick Answer

Magmeters and magnetic sink assemblies measure inline flow velocity in conductive liquids. They have no moving parts, low pressure drop, and direct volumetric output. Send pipe size, flow range, process temperature, and conductivity to Silver Automation Instruments for model selection and price.

What Magmeters and Magnetic Sinks Do

A magmeter is an electromagnetic flow meter. It works with water, wastewater, acids, caustic, slurries, and other conductive fluids. A magnetic sink in field installation is often a grounding ring or grounding electrode set. The grounding assembly gives stray current a low resistance path away from the sensor. This matters on plastic, FRP, or lined pipe.

The meter creates a magnetic field across the flow tube. Two electrodes pick up voltage generated by the moving liquid. That voltage is proportional to velocity. Because there are no rotors or gears, the flow path stays open. In practice, most engineers choose this setup for DN15 up to DN2000 lines.

A magmeter is not suitable for oil, diesel, or air because those fluids are non conductive. Use a Coriolis mass flow meter or a vortex flow meter for those services. Silver Instruments can supply both as a package with the magmeter.

Where These Meters Are Used

We have supplied magmeters for a desalination plant in Oman, a paint factory in Vietnam, and a dairy plant in New Zealand. These sites measure brine, wash water, lime slurry, and CIP return lines. Magnetic sink kits are common in chemical dosing skids in Southeast Asia and the Middle East.

For seawater reverse osmosis, a magmeter with PTFE lining and titanium electrodes works well as a seawater flow meter for desalination plant. For acid dosing, use PTFE or PFA lining with tantalum electrodes. For food grade, choose 316L electrodes and sanitary process connections.

Key Specifications Silver Instruments Offers

Silver Automation Instruments offers magmeter sizes from DN15 to DN2000. Accuracy is 0.5 percent of reading, with 0.2 percent optional. Conductivity should be at least 5 µS/cm for standard models. Some low conductivity versions work down to 1 µS/cm. Process temperature options range from -25 °C to 180 °C depending on liner. Pressure ratings go up to 40 bar for standard designs. Outputs include 4-20 mA HART, pulse, frequency, and RS485 Modbus. Display, remote transmitter, and battery powered versions are available.

Magnetic sink kits come with grounding rings, grounding electrodes, or straps. They help when the adjacent pipe is non conductive. We see this often in FRP, HDPE, and rubber lined installations.

Installation and Calibration Notes

Keep at least 5 straight pipe diameters upstream and 2 downstream. For control valve disturbances, increase upstream run to 10 diameters. The meter must stay full of liquid. Do not install at a high point where air collects. For horizontal lines, mount the electrodes in the 3 o clock and 9 o clock positions. This keeps them clear of sediment and air.

Calibration is by wet flow or electronic verification. New meters ship with a calibration certificate. We use accredited rigs in Nanjing, China. For critical batching, request a 5 point calibration report. For slurry service, verify the lining and electrode material with our engineers before ordering.

Industrial Applications

Water and wastewater plants use DN50 to DN600 meters for raw water, backwash, sludge, and effluent. Chemical processors use PTFE lined meters for sulfuric acid, sodium hydroxide, and ferric chloride. Food and beverage plants use sanitary magmeters for milk, beer, juice, and CIP solution. Marine and offshore operators use magmeters for ballast water and cooling lines. Talk to us about IMO and classification society appro