Contactless weighing

Article of 23 February 2018 

Contactless measuring and weighing with superconductor technology

Ultra-clean and germ-free processes are becoming increasingly important for industrial production, particularly in the medical and pharmaceutical industry. Surfaces in clean rooms must be sealed, easy to clean and effective to disinfect. A new concept using superconductor technology now enables contactless and precise weighing and measuring.

Keeping production in the laboratory free of germs and contamination is not easy. What is particularly problematic here is the work equipment used, for example test tubes, Petri dishes and also measuring devices such as scales. They are brought into the screened working space from outside and can introduce germs. If they are put down on the work surface, crawl spaces form underneath them, which are difficult to keep clean.

Hovering weighing pan

By using magnetic-field-based hovering technology – for example with superconductor technology – such restrictions can be circumvented in the future. One of the options is shown by the SupraSensor concept from Festo. It demonstrates how contactless scales work, for example how they would be useful in safety workbenches used in biological or chemical analysis.

At the heart of the application is a cryostat with a superconductor, which is permanently fixed on a set of precision scales under the work area. A weighing pan hovers above the area with a permanent magnet on the underside, which is coupled without contact to the superconductor and hence also to the scales. This is made possible by the special property of superconductors, which can make magnets hover at a defined gap when they are cooled to a certain temperature.

Hovering weighing pan: easy cleaning in a laboratory environment
Hovering weighing pan: easy cleaning in a laboratory environment

Easy to clean laboratory environment

Transferred to a laboratory environment, the workstation surface thus remains without disruptive elements on top and can be effectively and easily cleaned. Only the weighing pan hovers above the table top. If it is not needed, it can be removed and the whole working space is freely available.

Beyond pure measuring and weighing, the technology offers many other possibilities such as analytical density and viscosity determination, precise dispensing or monitoring reactive or biological processes. At the same time, the application with superconductors is very robust and stable both in terms of space and time: the materially intrinsic hovering function requires no control technology and remains in place for a long period even if the power supply is interrupted.

How the principle of contactless weighing works inside a sealed tube filled with liquid will be shown by Festo from 23 to 27 April 2018 at the Hannover Messe.

Contactless measuring and weighing with superconductor technology