Barcoding system simplifies differential weighing

A combination of Mettler Toledo LabX laboratory software and barcode-reading capabilities makes differential weighing of aeroplane fuel cells at China’s Donghua University easier and faster while still allowing researchers to ensure optimum fuel cell performance.

Capacity and performance of aviation fuel cells are directly related to how much active substance - in the form of a paste - negative plates contain. The paste is in close contact with a silver mesh and current collection plate to enhance electron transfer and improve capacity. If the negative plate winds up being too thick or too thin, capacity and efficiency are diminished. Fill control for paste application is critical for optimum fuel cell performance.

The process for assembling this part of the cells is relatively simple: weigh the silver mesh alone, then weigh it after paste application and moulding. The difference between the two equals the paste weight, which must reside in a certain margin for cells to perform as expected. Accuracy is critical; however, as in most manufacturing projects, speed is also important. The School of Mechanical Engineering at Donghua University turned to Mettler Toledo for not only accurate weighing but also process innovation that would enhance productivity.

Previously, the university’s process for tracking and matching up weights had been manual. Analysts weighed the cells, entered weights into Excel and updated their programmable logic controller (PLC) data file. Keeping meshes in order was critical, which was a cumbersome process when dealing with hundreds of them at a time. Today, using Mettler Toledo equipment including LabX software connected to an XP203S balance, weighing is essentially the only action researchers must take. The rest has been automated for significant time savings and fewer data-entry errors.

Weighing is initiated with just one click on the balance touch screen. Researchers scan each mesh with a barcode reader before and after the paste moulding process. LabX automatically identifies the mesh, calculates the before and after difference, and exports the data in final results suitable for PLC reading and quality control. The process is much easier and faster.

“The automation is really convenient. It saves us a lot of time and reduces workload,” said one project leader. “I don’t want to return to the days without LabX.”