Editor's Choice

Unlimited performance in limited spaces

February 2021 Editor's Choice

The new AF-E 400 is the culmination of KROHNE`s 70 years of expertise in electromagnetic flow measurement. It was specifically designed for industrial automation and is best in its class in terms of temperature range, accuracy, pressure drop and flow range.

Its unique compact sensor design makes this electromagnetic flowmeter perfect for use in tight spaces and for parallel installations in a variety of conductive liquid applications e.g. in cooling lines of welding equipment, bending machines and robots, or on chemical dosing skids.

The AF-E 400 features accuracy in every flow range, allowing optimal processing in automation. The round bore reduction of the sensor makes the flowmeter more resilient in terms of increased pressure, ensuring high accuracy over wide pressure and temperature ranges. Its integrated temperature measurement eliminates the need for an additional sensor.


Installation in tight spaces without crosstalk

An electromagnetic flowmeter typically carries the risk of crosstalk. It can influence the measurement of another device installed close to it because of magnetic field overlap. The AF-E 400 was developed with tight spaces in mind and guarantees maximum flexibility when it comes to installation.

Due to the special design of its magnetic circuit, field strength and electronics, these meters can be positioned in extreme proximity to one another – as close as 2 mm. They can thus be mounted in parallel without interference.

High temperature capability and accuracy

KROHNE examined some of the common issues with products in this segment and translated them into improvements across the board. AF-E 400 features for example the highest temperature capability. Continuous use at 90°C liquid temperature allows its operation in very demanding cooling and hot water applications.

The latest insights at KROHNE in magnetic field design and signal conversion enable the highest accuracy without adding costs. Furthermore, the combination of tight seals and laser welding guarantees high IP65 and IP67 ingress protection.

The integrated temperature measurement eliminates the need for an additional sensor, which minimises intrusion points in the pipe and provides more data from the process.

Extensive self-diagnostics

Thanks to extensive self-diagnostics, reliable operation can be assured. The meter continuously monitors several critical aspects including:

• Low supply voltage.

• Incorrect parametrisation.

• Flow range exceedance or short circuit on any of its outputs.

• Warning messages categorised according to NAMUR NE107 alert the user via the display and the IO-Link output.

Quick commissioning

The factory settings of the device make plug-and-play installation possible. For easy connection, a common M12 connector is used. The menu item descriptions on the full-colour display enable a quick understanding and easy setup without a manual. For more advanced functions like batching settings, totaliser functions, or hysteresis settings, a quick start aid is available and supplied in the packaging of the AF-E 400.


The AF-E 400 offers various output and communication options. The device runs on a 24 VDC supply voltage and features further output options like the traditional pulse, frequency and switch, but also more modern IO-Link and Modbus.

The plug-and-play IO-Link option of the AF-E 400 has many advantages for the user. Additional sensor data is transmitted to achieve maximum efficiency and cost savings while creating process transparency from the machine to the ERP level for optimising existing automation. IO-Link also enables automated device configuration without programming, which results in faster sensor installation or replacement.

Connecting industrial networks using the IO-Link communication standard is versatile, fast and efficient – from the controller down to the lowest level of automation. Analog signals are transported noise-free thanks to digitisation, which allows sensors to communicate at the fieldbus level. Continuous diagnostics and automated configuration can be run via the controller.

The IO-Link standard also offers significant advantages in terms of cabling, since no shielding is required, making cabling much cheaper. Moreover, thanks to integration through a master, users need less cabling to the control system and do not have to do any programming on the controller side.

Since the master automatically detects wrong or missing device IDs, cabling also becomes practically tamper-proof, and the master will always send the correct settings to the device.

AF-E 400 design in detail

The design of the AF-E 400 is specifically adapted for ultra-compact installation. Three small printed circuit boards are stacked in the device to enable the sleekest housing. This allows installation in distribution manifolds or areas where tubes are closely spaced.

Its 2 mm thick cast stainless steel housing also makes the AF-E 400 more robust than the plastic or sheet-metal housings used in some similar products on the market. Thanks to the rotatable, bright, full-colour display, excellent readability is guaranteed from every angle. Harmonisation of the housing design across connection types allows easy integration no matter what threaded connection or diameter is chosen.

Traditionally, flowmeters consist of a metal flow tube with a liner, which results in higher manufacturing costs and a more expensive end product. The AF-E 400 flow tube is made of high-quality, glass-reinforced, injection-moulded PEEK for a high-performance plastic flow tube that is resistant to a wide range of chemicals, temperatures and pressures. In addition, the magnetic circuit production is fully automated, which allows for highly repeatable production processes and reliability.

Where other producers sometimes choose a rectangular bore in combination with PEEK, the AF-E 400 flow tube has been designed with a round bore. This makes the flowmeter more resilient against increased pressure. As a result, the flowmeter maintains its accuracy specification over a wide pressure and temperature range.

The slight reduction in the round bore straightens inconsistencies in the flow profile and removes the need for inlet and outlet runs. In this way, the meter is suitable for compact installation close to bends or valves.

Thanks to only the slight reduction in the tube, the pressure drop is kept to a minimum. This means a high turn-down ratio without the risk of cavitation. As a result, the AF-E 400 has the widest flow range in its class.

Typical applications of the AF-E 400 in factory automation/machinery include:

• Flow measurement of conductive liquids in utility applications and industrial automation.

• Cooling water monitoring in bending, welding robots, injection moulding and web handling applications.

• Water consumption monitoring in washing installations (grit wash, car wash, industrial washdown).

• Flow monitoring in recirculation of hot and cold water.

• Dosing skids for reagents, catalysts or chemicals.

Product highlights

• Measurement of flow rate, totalised flow and temperature up to 90°C.

• Robust cast stainless steel housing (2 mm thick).

• Maintains accuracy over a wide pressure and temperature range.

• Round bore tube for minimised pressure loss and a high turndown ratio without risk of cavitation.

• No crosstalk.

• NAMUR NE 107 diagnostics.

• IO-Link enables transmission of more process data and automated device configuration without programming.

• Rotatable full-colour display.

For more information contact Deon Rampathi, KROHNE SA, +27 11 314 1391, d.rampathi@krohne.com, www.za.krohne.com


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