Electricity and Control December 2022

MEASUREMENT + INSTRUMENTATION

homogeneity of the slurry, the particle size, purity and viscosity – all need to be measured. Coating requires a dry film thickness in the micrometre range, with a coating accuracy of +/- 2 g/m 2 . Other quality parameters include surface quality and adhesion between the substrate and the coating. During drying, the speed at which the aluminium and copper webs are moving must be maintained at between 35 m/min and 80 m/min, and the temperature profile in the dryer zones maintained between 50°C and 160°C. Residual humidity and adhesion to the substrate and surface finish are also critical quality parameters. The calendering process demands a constant roller speed of 60 to 100 m/min. Factors influencing quality here include the roller temperatures, which may be between 50°C and 250°C. Slitting can introduce burr waste, so an important quality parameter to be measured is the degree of particle contamination during the cutting process. As a pressure process, the vacuum drying stage requires a working pressure of between 0.07 and 1 000 mbar, and a temperature between 60 and 150°C. After winding and assembly, the final process of electrolyte filling involves measuring pressure to approximately 0.01 mbar and measurement of the correct electrolyte quantity. Aging of the cell again involves measuring temperatures during an extensive process, with temperatures that can reach 50°C. With so many intricate processes and valuable materials involved, manufacturers cannot afford to scrap parts and start again if quality parameters go out of specification. Going digital enables top quality production Although analogue instruments are still employed in many industries, they are increasingly being replaced by digital versions. The accuracy and reliability of the latest generation of digital measurement solutions make them particularly suitable for the long and complex Li-ion battery production process. With analogue meters, data is transmitted as an electrical signal representing a particular measurement range, such as 0 - 500 ml/s in a flow metering application. The issue here is the potential mismatch between the transmitting range of an instrument and the input scaling range of the receiving instrument. If incorrect readings are created, this can lead operators to waste time looking for apparently lost measurements. Digital measurement eliminates this problem. By sending zeroes and ones from A to B, the displayed value will always be a faithful representation of what is happening in the process. This means that each stage of battery production is monitored to conform to the required parameters, ensuring safety, avoiding wasted materials and producing high quality products. Another advantage of digital protocols is that they allow multiple different values to be combined into the signal, whereas traditional analogue transmission allows only one signal to be sent at one time. With digital transmission, additional measurements can be sent with the primary measurement: density and temperature or pressure, for example. Digital instruments also promote quality and reduce errors because they are easy to set up and to use. Graphical displays

ABB supplies a range of digital instruments to measure pressure, level, temperature, flow and other parameters.

make it easier for users to operate measurement devices, reducing reading errors, and many incorporate set-up wizards, making commissioning easier. For example, pressure, level and temperature measurement devices from ABB feature a common HMI, reducing the need for training. Digital instruments are also more helpful in fault finding. Previ ous generations of instruments would simply activate a fault light, without any indication of what was causing it. Digital instruments automatically self-check the validity of their data, helping oper ators pinpoint which particular function is presenting a problem, and noting any difficulties encountered. Some advanced instru ments incorporate GSM, allowing users to connect to, say, a flow meter, remotely to obtain data and change configurations. With digital instruments communicating over protocols such as Fieldbus, there is more opportunity to manage them remotely. For example, for a major Li-ion battery manufacturer in Sweden, ABB has provided its Ability™ Field Information Manager (FIM). This is a device management tool that makes the configuration, commissioning, diagnostics, and maintenance of Fieldbus instruments easier and quicker, cutting connection time from between 15 and 30 minutes to only three minutes. Another solution provided to the client is ABB Ability Verification, which enables device condition monitoring in the cloud to reduce maintenance. Overall, digital instruments produce more accurate data, and are much more reliable and controllable than analogue instruments. By choosing the digital route, Li-ion battery manufacturers can safely produce the quality products that customers are looking for, and keep their operational and material costs to a minimum. □

For more information visit: www.abb.com/measurement

DECEMBER 2022 Electricity + Control

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