Driving the optimization of production ahead with new measurement components

Winterthur, April 2020 – Our journey to Industry 4.0 and the smart factory demands digitalization of the piezoelectric measuring chain. As well as continuously developing the necessary components such as the maXYmos process monitoring system, Kistler is also launching innovations such as the new mICA digital charge amplifier with IO-Link connectivity.

Piezoelectric quartz sensors are used to measure parameters such as pressure, force, torque and acceleration in many industries. This was made possible by the invention of the analog charge amplifier back in 1950. It converts the minimal electric charge from the quartz crystals into commonly used measurands. With the advance of automation and digitalization, sensors have an increasingly important part to play in production: in fact, they are absolutely essential to ensure that reliable data is available for Industry 4.0.

Overcoming the challenge of the transmission rate

Charge amplifiers are core components of the piezoelectric measuring chain, so they too must be adapted to the new conditions and requirements. Direct conversion of analog measurement signals into digital data is a major step along the path to the intelligent measuring chain in keeping with Industry 4.0. For charge amplifiers too, digital solutions offer advantages over analog technology. They allow continuous data exchange with higher-level systems, and no extra components are needed. Another benefit: the disturbance variables that usually occur in analog mode due to inductive or capacitive couplings are eliminated with digital signals, because the raw analog signal is already digitized in the amplifier.

By launching the dICA (digital Industrial Charge Amplifier), Kistler has now become the first provider in the world to offer a solution that features all these advantages. The 5074A digital charge amplifier communicates via Industrial Ethernet and features a very wide measuring range, from 20 to 1,000,000 pC. Up to four channels offer excellent flexibility and control: each channel can be activated individually with precise timing, so different processes can run in parallel via one dICA. But most important of all, this charge amplifier achieves an acquisition rate of up to 50 kSps per channel, so real-time transmission of measurement data becomes possible with cycle times of up to 100 μs.

Cutting-edge connectivity via IO-Link

The size and weight of every additional component are critical, especially when sensors are used on moving elements of automation technology such as robot arms. This creates the need for small, lightweight digital charge amplifiers that save on additional hardware as compared to compact analog amplifiers. In many of these applications, high transmission rates and wide measuring ranges with multiple channels are not the main priorities. Kistler has specifically developed the 5028A charge amplifier for applications of this type, as an alternative to the 5074A: with just one measuring channel, it offers the advantages of compact design and low weight combined with efficient communication via IO-Link.

Thanks to these features, the mICA – miniature Industrial Charge Amplifier – can be integrated seamlessly into digital architectures. It includes both analog and digital interfaces, with direct data access via the digital interface. Thanks to IO-Link, new parameters are transferred directly in case of system changes. One point to note here is that the cycle times of the amplifier and the higher-level system must match, so as to prevent falsification of the measurement curve. In digital mode, the mICA achieves cycle times as low as 0.6 ms – fast enough for most industrial applications. Users who need higher transmission speeds to capture or control very fast processes can choose analog mode: for this purpose, the mICA is fitted with a reset/operate input.

These two digital charge amplifiers – the 5074A and the 5028A – make it possible to digitalize the measuring chain in many cases where this option was technically unfeasible or economically unviable until now. Maximum digitalization and top speed with dICA, or maximum flexibility and compact dimensions with mICA – digital measurement technology from Kistler supports smart factories and Industry 4.0.

State-of-the-art process monitoring

The picture is similar for measurement systems that use sensor data to visualize processes and readjust them as required. The maXYmos process monitoring system from Kistler now ranks as the standard for a diverse range of applications in many sectors. Examples include the assembly of connectors and medtech products as well as the production of automotive components. The three variants of maXYmos – BL (Basic Level), TL (Top Level) and NC (Numeric Control) – are equally suitable for use in manual workstations and highly automated production lines.

maXYmos correlates two variables (X and Y – often force/displacement or force/time) and uses evaluation criteria that can be selected by the user to check whether their profile meets the desired requirements in the machining or production process. This information significantly improves both the transparency and reliability of the process: based on data supplied by sensors, users can optimize the process and (for example) set up automatic separation of good and bad parts. The benefits: enhanced product quality with increased resource and cost efficiency.

In the TL and NC variants, the latest version of maXYmos (1.7) now features OPC UA capability for the first time – so data consistency and networking with higher-level systems are significantly improved. Data relating to one product cycle is saved in a dedicated OPC UA event – a key factor in ensuring data consistency. And because maXYmos can now communicate directly with the machine control, functions such as fully automated separation of bad parts are possible – a major advantage, especially when maXYmos is installed in highly automated production cells.

Digitalization of the measuring chain unleashes potential

Development work on Kistler's process monitoring systems never stops, and the company recently unveiled a new version specifically designed for the medtech sector. Its name: maXYmos TL ML. This version is specially optimized for measuring ranges with small forces, and it features FDA-compliant user management to track all changes to the process.

With the latest process monitoring systems in the maXYmos series as well as the dICA and mICA digital charge amplifiers, Kistler is opening up even more scope and many more opportunities for its customers to optimize their industrial production. The ongoing digitalization of the piezoelectric measuring chain will be a major focus of Kistler's future development work, with one goal in view: to offer yet more added value from the deployment of measurement technology in industrial production.