Nowadays, modern weighing instruments increasingly make use of digital load cells, such as the FIT® load cells (Fast Intelligent Transducer), from HBM. Here, the measured value is digitized directly in the load cell, and then transferred to a display and evaluation unit, the so-called scale electronics. The big advantage of digital data transfer is that there is practically no interference on the measuring leads.
A suitable way to prevent manipulation of the measured value during transmission is to encrypt it. The DIS2116 digital scale electronics from HBM, in conjunction with type C16idigital load cells, for example, allow legal-for-trade, manipulation-proof weighing instruments to be set up. The data are transferred from the load cells to the scale electronics in encrypted form. The Advanced Encryption Standard (AES) is used here, with a 256-bit key. Using this modern encryption algorithm also meets the requirements of WELMEC guideline 7.2. As manipulation is prevented during the transmission of data, the legal-for-trade capability of a scale is always ensured.
But there are further options available with digital signal transmission. These include, for example, transferring the data over a wireless transmission system. This automatically gives the transducers electrical isolation, whilst simultaneously providing greater physical separation between the transducers and the scale electronics. As digital load cells also transfer status and error messages in addition to the actual measured values, it is very easy to implement asset and facility management at the same time. Faulty transducers are easily identified and it is a simple matter to replace them, as required. This greatly reduces service and maintenance expenditure.