Ultrasonic Flow Meter with IO-Link - Inline - DUK

Ultrasonic flowmeter combines temperature-compensated measurement for various media with IO-Link

A PC interface enables measurement of media-specific volume flows even at changing temperatures

Whether in the pharmaceutical industry, water treatment or food production: If non-conductive media flow in a chemical process, ultrasonic flow meters are usually installed for monitoring. For monitoring, the measuring devices require short response times and a high degree of calibration freedom, otherwise incorrect metering or insufficient repeat accuracy will occur. The maintenance-free ultrasonic flowmeter type DUK with the newly developed C3T0 compact electronics from KOBOLD Messring GmbH provides a remedy here. Due to the extensive possibilities for on-site programming, the DUK is suitable for cross-industry use for diverse media.

Accurate measurement of all media

The flow meter of the DUK series previously covered the needs for water and water-like media. Now, by incorporating additional media parameters, the proven DUK is used for volume flow measurement of almost all homogeneous, Newtonian media, even without electrical conductivity. Examples include demineralised water (deionate), water-glycol mixtures with different mixing ratios, oils and aliphatic hydrocarbons such as ethanol, as long as ultrasonic waves can pass through.

This is possible by combining the DUK with the new smart electronics, onto which the file with media-specific data is imported from the PC and used from that point on. KOBOLD also sells the corresponding PC interface with USB connection. The associated software "Mediator Tool" is provided to the customer free of charge. On customer request, the units can also be set and calibrated at the factory. Either the DUK can be set for a fixed operating point or a configuration for different temperature ranges can be stored.

The units of the DUK family operate according to the transit time difference method. This is based on the fact that ultrasonic waves in a medium are influenced by the flow velocity. Two sensors mounted opposite each other in the pipeline work simultaneously as transmitters and receivers of ultrasonic signals. If there is no flow, the transit time of the two signals is identical. When the medium is flowing, the transit time against the direction of flow is longer than the transit time of the signal in the direction of flow. The transit time difference determined by a microprocessor is proportional to the volume flow. The temperature has an influence on the speed of sound and thus on the accuracy of the measurement result. Therefore, the current temperature of the medium is measured by means of a temperature sensor integrated in the unit and compensated for by the electronics when calculating the volume flow.

Wear-free and universally applicable

"Ultrasonic flowmeters do not have moving parts such as impellers, which is why they do not show any signs of wear. Therefore, these devices have proven themselves for flow determination of diverse media," explains Raza Ali Agha, Sales Manager at KOBOLD Messring GmbH. "This wide range of applications leads to different installation situations, as the measuring devices are used in various industries and processes." The nominal diameter of the connected pipes and the possible alignment during installation and the integration into process chains, such as the precise regulation of the coolant supply, influence the choice of a suitable device. Particularly in the context of metering processes, the measuring instruments offer the possibility of programming intermediate values in order to document the quantities.

For this reason, KOBOLD Messring GmbH has developed universal flow meters with IO-Link in the form of the DUK product, which are suitable for almost every measuring situation and, in addition to response times of less than one second, guarantee a high degree of programming freedom. This is ensured by the numerous functions, such as temperature measurement or flow rate, which can be set in a few steps in the menu on quick selection keys (so-called hotkeys).

Valuable customer feedback

"During the conception phase, we used the experience reports of our customers from various industries as a basis for developing a flexible and reliable universal device specifically for non-conductive media. With the extension of the DUK by the C3T0 option, there is now a measuring device for almost every measuring project," sums up Agha. "At the same time, the measuring devices are prepared for future media. They are simply changed over by file upload via USB when process conditions change."

Use under extreme conditions

In addition to the temperature measurement function, the DUK is often used for small nominal pipe sizes. The DUK covers a large measuring range for volume flow measurement according to nominal width - with a measuring range factor of up to 250.

"The flow meters have two individually configurable outputs, which, depending on the setting by the customer, function as a pulse, alarm or analogue output, for example," explains Agha. "This makes them easier to integrate into different processes or auxiliary circuits and, with their short response times, they represent real added value." The colour multi-display can also be digitally rotated in 90° increments, so there is no need for a different model when changing locations and the display is independent of the position of the connections.

The desired dosing process can be started and stopped both locally on the display and via an external control input. The desired quantity is adjusted on site via the keys. "Particularly in sensitive processes such as tablet coating, precisely measured partial quantities and good response times are indispensable," confirms Agha.

The basic building block for every measurement project

The flexibility of the unit family is reflected in the user guidance and the range of functions. Almost all settings can be conveniently set on the display via four optical keys on site. Functions such as temperature measurement, partial quantity display or maximum flow rate can be assigned to the hotkeys mentioned, so that it is not necessary to constantly navigate through several control levels in the menu. This can be done just as safely with most gloves. The multi-line display offers a better overview than comparable devices and shows the corresponding unit or other additional information next to the measured value. This clarity is further enhanced by the multi-colour display: for example, the colour changes when a certain flow volume has been reached. This allows the user to see from a distance when a certain quantity has been dosed or a limit value has been exceeded.