1 Introduction

Digital technologies have advanced dramatically in recent years, including big data concepts, cloud computing, blockchain, embedded systems, and the Internet of Things. Additionally, they have fostered the emergence of brand-new technological industries and data-driven marketplaces, such as Industry 4.0, artificial intelligence (AI), and machine-learning-based smart services offered through digital platforms. The exponential growth of computing and, storage capacities, as well as the increasing high speed of data exchange, and the affordable availability of versatile sensors have opened up new possibilities for creating networks between objects and exploitation of the data and information stored. The catalyst will advance several fields including robotics, the Internet of Things (IoT), digital pathology, distributed ledger technology, synthetic biology, super-fast intelligent communication networks, additive manufacturing (AM), and autonomous systems. Further, the pandemic of COVID-19 has accelerated the rate of digital transformation around the globe in different fields including metrology. In every industry, digital transformation has a variety of benefits and implications, with multiple platforms permitting communication in a variety of media [1,2,3,4,5]

The metrology or science of measurement is vital to any country's industrial development and growth. It acts as an excellent tool that facilitates the advancement of technology. It also fosters global competence and trust. With the introduction of higher-quality products made possible by technological advancements, our industries will be able to compete on a global scale, overcome trade hurdles and constraints, and eventually meet export targets. This translates to increased industry expansion, economic growth, and societal upliftment due to fast industrialization [6,7,8,9].

In the twenty-first century, entering into and sustaining business, is becoming more diversified, requiring day-by-day innovations, expansions, and competition more than ever before, especially in the processes and production methods. As a result, a nation's need for accurate and trustworthy measurements is evolving. Technological advancement will be significantly impacted by the precision and accuracy of measurements made during the production process [10, 11]. To achieve this goal, several countries have a national measurement system (NMS), which is a network of laboratories, calibration facilities, standards, and certifying bodies that are part of their national quality infrastructure. The national measurement system (NMS) is the organizational and technological framework that guarantees a dependable and widely accepted basis for measurements that may be linked to SI units [3, 12,13,14]. Figure 1 shows the linkage of NMS in the Indian context as a linkage of National and International associated bodies. The dissemination of measurement standards to industry, government, strategic partners, and academics in many parameters through apex-level traceable calibration certificates, training, and consultation services is critical and it translates into their economic growth and quality of life [8, 15,16,17,18]. However, organizations will be able to get more value out of their efforts in the future by identifying, comprehending, and addressing emerging risks related to metrology through its digital transformation. The present paper discusses the need and impact of the digital transformation of metrology in the modern era.

Fig. 1
figure 1

National and International linkage of Quality Infrastructure of India

Full size image

2 Metrology 4.0

AI-based solutions are essential for Industry 4.0, upstream and downstream in the development of products. Algorithms that modify the manufacturing process will provide constant, effective, and, most importantly, repeatable production with approximately zero failure rates. Fast, non-contact optical metrology devices can record 3D data as components are made, which can then be provided directly to the quality control team for analysis of compliance with design intent by comparison with 3D CAD models. Any problematic locations can be marked, and CAM files can immediately be adjusted [19,20,21,22].

A single software platform can support assessments of roundness, surface finish, contour, and topography thanks to metrology 4.0, a revolution in industrial measuring technology. With the help of cutting-edge software, measuring science and digital technologies are combined to provide a potential tool that pushes the limits of precise technology. Industry 4.0 is powered by metrology 4.0, which has advanced features including real-time data, virtual displays, customized reporting, and remote monitoring, to mention a few [23, 24].

The creation of "Virtual Instruments" and "Digital Twins" is the result of advanced mathematical models of measurement tools. These technologies let organizations develop virtual representations of physical products, processes, or services using real-time data, mockups, algorithms, and AI. These technologies often cost less than physical prototypes, allowing companies to produce and test an infinite number of variations [25,26,27]. The qualitative difference between Virtual Instruments and Digital Twins is shown in Fig. 2.

Fig. 2
figure 2

Virtual Instruments and Digital Twins

Full size image

The core of Metrology 4.0 and all advanced production systems are learning metrology systems that are more intelligent, flexible, and quick. These metrology solutions will upgrade the manufacturing towards more inventive, well-designed, and high-quality goods while significantly reducing downtime in networked factories. Currently available metrology solutions in the market can be utilized to improve manufacturing efficiency at all levels, even though there are a lot of advances in this field on the horizon.

3 Smart Manufacturing

The manufacturing industry is presently undergoing a thorough transformation. This transformation is primarily brought on by rising automation, digital transformation, the fusion of the digital and physical environments, the development of additive manufacturing as an industrial and manufacturing technology, the intensive use of data and analytics, manufacturing challenges, human, economic, and societal evolutions, as well as the blending of information technology and operational technology. The objective of a Smart Manufacturing environment is to automate as many processes as possible to boost production efficiency. The core of this production system has to evolve, and more precisely, measurement analysis. Digital models provide pre-established data to measurement systems through measurement programmes with optimal and secure trajectories, measurement rules within the context of quality performance management, and quality problem anticipation. As a result of advancements in data and analytics, AI, and machine learning, as well as the diverse range of equipment manufacturers in the market, factories now have access to a vast array of technological options for enhancing their processes. Thus, Smart manufacturing can be expressed as the fully-integrated, collaborative manufacturing systems and collaborative robotics that respond in real-time dynamic conditions and demands in the supply network, the smart factory, and customer requests [28,29,30,31,32]. Figure 3 represents some of the major technology linkages that supports smart manufacturing.

Fig. 3
figure 3

Integration of technologies for smart manufacturing

Full size image

Key components of smart manufacturing are a consolidated array of technologies and an integrated digital infrastructure. Companies require centralised access to data from all sources. A strategic big picture is made feasible by cutting-edge analytics and visualisation. While AI and machine learning enhance research, analysis, and automated processes, edge computing offers a secure data buffer between local sites and the internet or cloud. Every industrial asset or component of the system must also have its own identity (IP address) and wireless open connection in order to support smart manufacturing. Intelligent sensors are included into each individual gadget to convey vital data to on-site or cloud-based central data management.

4 Metrology in Digital Era

At the 26th meeting of the General Conference on Weights and Measures (CGPM) in Versailles, France, the BIPM's Member States resolved to revise the International System of Units (SI), which means that all SI units will henceforth be defined in terms of constants that characterise the natural world. This will ensure the SI's long-term stability while also allowing new technologies, such as quantum computing, to be used to implement the definitions [6, 17, 33].

The SI system is widely utilised in scientific and technological research and development, as well as in international trade and commerce. SI units are an integral aspect of modern metrology and, as a result, have become the bedrock of modern science and technology. The metrology community has begun outlining how metrology will develop in the twenty-first century since the redefinition of SI. The word "digital metrology" can be used to describe potential advances and substantial modifications to current metrological services as well as new metrological services required by digital trends. Its transformation into a fully digital representation is required to facilitate efficient processes within industry, the quality infrastructure and its organisations, and modern research and development globally. Strong, clear, and machine-actionable digital representations of units of measurement are required for such a digital representation. Representatives from OIML and CODATA have already shown their willingness to collaborate. Collaboration with CIPM on the SI Digital Framework and its dissemination in compliance with the Findable, Accessible, Interoperable, and Reusable (FAIR) principles [11, 34,35,36,37,38,39,40]. Figure 4 represents the Integration of digital infrastructure with FAIR principles.

Fig. 4
figure 4

Integration of digital infrastructure with FAIR principles

Full size image

The year 2022 theme was "Metrology in the Digital Era". The theme was chosen since digital technology is one of the most interesting subjects in society right now and is transforming metrology. The digital advancement of science and technology depends heavily on reliable and impartial data. The key to moving our sector to the next stage in the digital milestone is the high-quality data that is produced as a result, which is based on measurement standards [41, 42]. World Metrology Day is an annual celebration day commemorating the signing of the Metre Convention on 20 May 1875. The Convention established the guidelines for international cooperation in measuring science and its commercial, industrial, and societal uses.

To achieve metrological transformation, the development of Digital SI units (D-SI) became an essential requirement for upcoming industries. Because processes in the modern industrial revolution are expected to be precise, rapid, safe, and adaptable, touchless calibrations are required. As a result, an unprecedented demand for digital metrology is emerging for the digital transformation of metrological services, as well as remote calibrations whenever possible, in order to stay up with time-efficient error identification and reduce production delays. The complete calibration procedure can be done online and in real-time if the calibration/reference laboratories and the client laboratories can be connected via electronic methods for data exchange rather than instrument transport. This would result in immediate time and financial savings. It can be accomplished by designing a system for producing, transferring, and controlling calibration data that compares the values of the reference standards to the values of the artefacts without affecting the calibration's accuracy and traceability [43, 44]. The following sections gives a thorough description of how digital metrology developed, its impacts, potential consequences and challenges for metrological services.

4.1 Digital SI Units (D-SI) and Metrological Services

The International Committee for Weights and Measures (CIPM), which oversees the metrological activities carried out by parties to the Metre Convention, has established a Working Group on the "Digital SI" in response to the need to strengthen support for the SI in a digital environment. As mentioned, a “SI Digital Framework” offers the key building blocks for a comprehensive digitalization of the global quality infrastructure (QI). Finding a common identity in digital transformation is a challenge for leading QI organisations. Figure 5 shows the possible objectives of the SI Digital Framework. This framework will support a description of the system being measured, the methods used to take the measurements, and the processes involved in arriving at the final measurement findings. The framework would increase machine readability from basic capabilities to a comprehensive knowledge representation that can be used by machines. Machine-actionable data will enable the application of ML and AI technologies and allow automatic assessment of the origin, metrological traceability, and fitness-for-purpose of datasets. The development of sophisticated algorithms and software tools that can quickly and precisely evaluate vast volumes of data has been made feasible by digital technology, making it possible to identify and repair measurement errors in real-time. The traceability chain could be benefited from this metrology's evolution. In order to ensure that measurements are traceable and consistent across various measuring systems and laboratories, it is possible, for instance, to track and verify the authenticity of measurement findings by using digital signatures and digital calibration certificates (DCCs) [40, 45].

Fig. 5
figure 5

Possible objectives of the SI Digital Framework

Full size image

Each country's National Measuring Institute (NMI) is thus a guarantor of measurement accuracy, consistency, and testability, and is a strong supporter of worldwide harmonisation in these areas. In order to achieve these goals in a digitalized environment, NMI should focus on producing DCCs that are equivalent to real and virtual measurements in the "Metrology for Virtual Measuring Instruments." In addition to DCCs, it is possible to read digital system data right away and use it automatically going forward. This process can be applied to any other metrological document, such as digital test reports or machine-readable certifications of conformity. The information provided in these articles can be utilised globally with the use of appropriate technical interfaces. Figure 6 depicts the overall layout of a possible national infrastructure as well as digitalization using DCC. This figure makes it clear how crucial function calibration certificates serve with different NQI bodies.

Fig. 6
figure 6

National quality infrastructure with possible DCC implementation

Full size image

On DCC projects, world scientific community are putting together software tools and creating real-world examples. These details are part of DCC's fundamental structure: Initially, information of primary interest is present in the administrative data. They are essential for distinctive identification. Then, the SI-based information related to measurements results, such as identifier, measured value, expanded uncertainty, expansion factor, unit, and time, etc. Aside from the SI unit system, other unit’s system can also be expressed. Next, comments and graphics are saved for as long as possible. The DCC is finalized with a human-readable file that might be in pdf form and modelled after the analogue calibration certificate.

In other nations, legal metrology is already being digitalized, and the OIML Bulletin's recent issue contains a useful summary of these works. DCCs were established by the German National Metrology Institute (Physikalisch-Technische Bundesanstalt, PTB) and the National Physical Laboratory (NPL), United Kingdom to collect and organise standardised metadata and data about calibration. The PTB has created a "European Metrology Cloud," and the Interamerican System of Metrology (SIM) has task forces dedicated to "Metrology for Digital Transformation" (M4DT), which share information on automating laboratory operations, cloud technologies for metrology, and DCCs. In fact, manufacturers operating in the European and/or Latin American markets may have already thought about how to interface with these digital systems. The National Institute of Standards and Technology (NIST), USA has initiated work in the United States to realise the "Digital NIST," with an initial focus on DCCs and their possible modification for SRM® Certificates of Analysis and NIST calibration reports [35, 46,47,48,49,50].

4.2 Challenges in Digital Metrology

The current method of providing metrology services has its own set of drawbacks since it requires a significant amount of time to follow established protocols, including paperwork. Furthermore, the lack of a real-time monitoring mechanism makes it difficult to follow the progress of service as well as concerns with document verification. Different researchers and industry professionals around the world are considering various digital technologies, such as Big Data analytics, the Internet of Things (IoT), Artificial Intelligence, blockchain, cloud computing, and so on, to provide metrology solutions that result in automated and paperless systems with better customer service. The QI, which includes metrology, accreditation, conformity assessment, norms & standards, and market surveillance, is facing a significant challenge from digital transformation. Figure 7 shows some of the major challenges with digital metrology. These challenges summarize as;

  • Calibration and Traceability: One of the major challenge with digital metrology is ensuring that measurements taken by the digital instruments are accurate and traceable. This requires the development of strict calibration protocols and standards that ensure that the consistent measurements are being taken. It is also have clear chain of traceability for each measurement, which can be more difficult with digital instruments.

  • Data Management: Digital metrology generates large amount of data, which can be challenging to process and analyze. It is important to have effective data management and analyzing tools to ensure that the measurements are accurate and reliable. Data security and privacy are also important consideration in digital metrology.

  • Software and Firmware updated: Digital instruments often require software and firmware updates to function properly, which can be challenging to manage. These updates may be necessary to fix bugs or improve functionality.

  • Training and Expertise: Digital metrology requires specialized training and expertise to operate effectively. This can be challenges for the organizations that do not have resources to invest in training and certification of their staff.

  • Cost: Digital metrology can be expensive, particularly for the small organization. The cost of equipment’s, software and training can be significant barrier to entry, and may require substantial investment to ensure that measurements are accurate and standardized.

Fig. 7
figure 7

Challenges in Digital Metrology

Full size image

5 Conclusion and Way Forward

An important trend in the growth of the manufacturing sector and a way to boost competitiveness among industries is smart manufacturing. The development of digitally connected factories will be supported by better measurement. As a result, production will move more quickly and with better-designed, higher-quality items. The moment has come when it is necessary to start modernizing the inspection procedure and utilizing the more advanced measuring equipment that is becoming available. Metrology in IoT measurements improves the data's usefulness for intended applications and outside parties. A data economy, where markets can guarantee the quality of data sold, will also be enabled by trusted data. This will boost the overall flow of reliable information, which will be advantageous to all stakeholders. Further, additional work such as certifying the digital certification, setting up a system for storing and disseminating digital certification, protecting the physical to digital traceability link, and maybe using digital twins, etc. is needed to offer the opportunities. The development of Digital SI, which will offer a common data model for metrological data, and Digital Calibration Certificates (DCCs), which will replace conventional paper-based calibration certificates, are two examples of how metrology is currently transitioning to digital data formats. The infrastructure for metrology is being globally digitalized, but there is still a range of challenges to overcome. Before they can be standardised globally, work still needs to be done on the technologies and the associated infrastructures.