Surface metrology is of key importance for applications in a wide range of fields, such as, aeronautics, automotive, the semiconductor industry, tribology and healthcare to name only a few of the most relevant. The use of calibrated physical standards is imperative to guarantee the reliability of the results obtained in industry and laboratories using different measurement instruments and techniques, such as contact stylus profilometers, coherence scanning microscopes, confocal microscopes and focus variation microscopes. Most of them use step height or depth setting standards for the calibration in the Z-axis. Accordingly, work has been performed at the Spanish Centre of Metrology (CEM) to provide traceability for the first time at a national metrology institute, using the combination of a SIOS metrological nanomeasuring machine (NMM) with a laser focus sensor for extended range (LFS-e). This paper focuses on measurements with this system on the Z-axis, which is the coordinate with the most stringent requirements for these techniques. This primary instrument with direct traceability to the metre realisation has proven to be a reliable tool for the calibration of a wide variety of groove and step height standards. The combination NMM + LFS-e is able to calibrate these physical standards within a range of up to 5 mm. Measurement results of step height/groove standards ranging from 9 nm to 900 & micro;m obtained using this system are presented. These calibrated standards provide traceability to other surface measurement techniques in CEM's Micro and Nanodimensional Metrology Laboratory. The reliability of this traceability route is demonstrated through the results obtained in the International Bureau of Weights and Measures' (BIPM) international comparisons of surface material standards calibrations, using NMM + LFS-e system and contact stylus profilometry techniques. These results demonstrate a robust traceability route validated at the highest international level.
This work reports on the current development status of a 40Ca+ trapped-ion optical frequency standard at Centro Español de Metrología. The system is based on available commercial components with a dedicated control and integration infrastructure to implement ion loading, trapping, cooling, and interrogation. Key elements of the system include a linear Paul trap, a multi-wavelength laser platform for ion preparation and interrogation, and an ultra-stable spectroscopy laser stabilized to a high-finesse cavity. Recent progress include the installation of the experimental infrastructure, integration of the laser and control systems, and the successful trapping and detection of calcium ions. Ongoing work focuses on spectroscopic characterization of the clock transition and the evaluation of systematic frequency shifts. These developments represent a significant step toward the realization of a fully operational optical frequency standard and its future dissemination.
Magnetic field measurements are critical for applications in renewable energy, electric mobility, and medical diagnostics. To ensure metrological traceability and measurement uncertainty control, this work establishes a traceability chain at the Centro Español de Metrología (CEM), using as primary standards nuclear magnetic resonance magnetometers. The chain extends from a few microtesla to several tesla, with uncertainty components evaluated for generator drift, field homogeneity, probe temperature effects, linearity, among other sources of uncertainty.
This paper describes methods to calibrate high value resistance standards with the help of an Ultrastable Low Noise Current Amplifier and a Resistive Voltage Divider. By combining both instruments shorter traceability routes up to teraohm range can be developed, with reduced uncertainty
The Spanish National Metrology Institute (CEM) has developed a primary magnetic laboratory that requires continuous updates to meet the evolving industry needs. This paper outlines the traceability chain of CEM's magnetism laboratory, which begins with a Nuclear Magnetic Resonance (NMR) sensor capable of measuring from 40 mT to 1.5 T using multiple probes. The secondary standards used in the lab are detailed, ensuring high precision and reliability in magnetic measurements.
