Sensor Performance for Automation

Hygiene and reproducibility are crucial factors in the food industry for efficient and safe production with a high degree of automation. This affects the measurement technology used. As there is no such thing as a one-size-fits-all approach to automation, the Anuga FoodTec exhibitors' programme of systems that can be easily integrated into the lines is broadly diversified. It ranges from simple control valves and sensors to decentralised solutions that open up a wide range of diagnostic options.

For hygienic production in particular, measurement technology manufacturers offer solutions tailored to the demanding requirements of the food industry. Thanks to the high-quality materials used, they can withstand even aggressive cleaning agents and meet all EHEDG, 3-A Sanitary and FDA standards. The sensors used feature a hygienic design with no gaps or dead space, front-flush process connections and a robust stainless steel housing that meets all aspects of CIP (cleaning in place). There is great potential for savings in the area of CIP applications, which are so important for beverage producers. Highly accurate measurements and short reaction times significantly reduce the energy and media consumption. For example, Baumer offers hygienic sensors that quickly and precisely measure parameters such as conductivity, flow rate, temperature, fill level and pressure. One current example is the ultra-compact PAC50 conductivity sensor. In order to minimise the dimensions, the designers pushed the boundaries of what is physically possible during development. The housing is no longer than 60 millimetres, and even the display is a modest 32 x 25 millimetres. The sensor is characterised by high performance and temperature robustness up to 140 degrees and is ideally suited for use in small lines in the brewing and beverage industry.

Thanks to the patented Surface Acoustic Waves (SAW) technology, the FLOWave flowmeters from Bürkert Fluid Control Systems can completely dispense with sensor elements in the measuring tube that come into contact with the medium. The liquids to be measured do not come into contact with sensor elements and there are no dead spaces. This means that the FLOWave Type 8098 measures the flow rate under completely hygienic conditions. The multi-parameter sensor can measure the flow rate, density and temperature as well as the original wort concentration, making it ideal for use in breweries. The high repeatability of the measured value ensures consistent brewing parameters even if there are changes in the raw materials for the respective types of beer. As the measuring tube is no different from any other straight pipe section in the line in terms of fluid mechanics, there is no pressure drop. The measurement works equally well in both still and fast-flowing liquids. SAW technology is the latest trend in sensor technology: In the past, suppliers of process measurement technology tried to develop sensors for every requirement. Today, they solve the increasingly individualised tasks in the food industry using innovative sensor software concepts.

Experts see a trend towards multi-parameter systems in smart sensors, which are able to control the increasing complexity of hygienic processes. They enable existing technologies, traditionally used for flow rate and fill level, to measure properties such as density or viscosity. Additional process data and diagnostic information allow precise predictions to be made about the current condition of the line and its future maintenance requirements. This reduces downtimes and the risk of contamination. With its three measuring principles – pressure, continuous fill level and limit level – the new "Compact Line" from Endress+Hauser helps, for example, to increase productivity. While the IP69 rating of the housings ensures efficient cleaning of the measuring instruments, the welded stainless steel construction also withstands sterilisation on site (Sterilisation-In-Place, SIP). This 360-degree hygienic design is guaranteed to a large extent by Memosens technology. It has revolutionised liquid analysis and stands for digitisation of measured values directly in the sensor head, i.e. for contactless, digital signal transmission and for diagnosis and storage of all relevant data directly in the sensor. Moisture and corrosion no longer stand a chance. With all common types of field bus, Memosens systems are open to all process control and asset management systems. This allows users to purchase Memosens-compatible components from different suppliers, each of which operates independently, and to combine them as required.

Media-independent measuring principles are particularly popular with food producers. With the CombiLevel PLP70, Baumer is once again making continuous level measurement significantly more flexible. The potentiometric level sensor automatically adjusts to homogeneous media with very low conductivity (greater than five microsiemens per centimetre) and enables user-friendly process monitoring thanks to the large touch display. The level sensor with IO-Link interface offers a response time of less than 100 milliseconds and is ideally suited for highly dynamic processes with rapid fill level changes. This means that the sensor is pushing into previously uncharted territory, because: "The PLP70 is particularly profitable when used with a high number of product types or when changing media frequently. Thanks to the media-independent measuring principle, the sensor offers the highest accuracy and repeatability even in the most demanding applications," says product manager Julian Budde. As examples, Budde cites processes with pasty, adhesive or foaming media that are difficult to measure and have a low conductivity. Thanks to the robust and crevice-free sensor design, the parts in contact with the process can be cleaned easily and reliably. In addition, thanks to its float-free measuring principle, the sensor minimises the risk of malfunctions and sensor failures, thereby increasing process and plant safety.

Equipped with IO-Link and versatile hygienic adapters, the Vegapuls 42 level sensor also meets the needs of the industry. These include solving complex measurement tasks faster, easier and more cost-effectively. With its IO-Link portfolio, Vega brings the advantages of radar measurement technology to the hygiene-sensitive processes of the food industry. Radar is often a better alternative for continuous, non-contact level measurement here, and, in contrast to ultrasound, is not influenced by process and environmental conditions. "We've carefully integrated all the crucial functionalities at the highest state of the art into the sensor," explains product manager Marvin Moser. Accordingly, the Vegapuls 42 is based on the best radar chip currently available on the market. At the same time, the designers consistently avoided over-designing it. In short: Vegapuls 42 is reduced to the essentials. It is tailor-made for all standard applications in which more functionality would only make work more complicated. Specifically, this means that the sensor is designed for medium measuring distances of up to 15 metres or temperatures of up to a maximum of 150 degrees Celsius. The equipment is designed for production cycles, dosing processes or downstream processes such as those found in conveyor and filling systems. It ensures reliable processes wherever the levels of liquids and bulk materials change quickly and require continuous monitoring.