Overview
ISO/TS 22292:2021 - Nanotechnologies: 3D image reconstruction of rod-supported nano-objects using transmission electron microscopy (TEM) - is a technical specification that provides practical guidance for producing reliable three‑dimensional reconstructions of nano-objects supported on electron‑transparent rod-shaped supports. The document covers the workflow from sample preparation, through TEM data acquisition, to image alignment, 3D reconstruction, and extraction of size and shape measurands for nanoparticles and other nano-objects in the nanoscale (≈1 nm to 100 nm).
Key topics and requirements
- Scope and applicability
- Procedures apply to samples dispersed on or within an electron‑transparent, rod‑shaped support; useful for detailed 3D analysis of a limited number of objects.
- Sample considerations
- Guidance on choosing rod diameter and sample preparation variants (including options that enable combined 2D TEM and 3D analysis).
- Instrument factors and TEM/STEM setup
- Recommendations on microscope configuration, calibration, accelerating voltage, collection/convergence angles, magnification, detector pixels and acquisition timing. An informative annex covers STEM variations.
- Data acquisition
- Procedures for acquiring tilt-series 2D projections suitable for tomography.
- Data alignment and volume reconstruction
- Steps for aligning projections, reconstructing 3D volumes and software considerations (Annex C references tomography and visualization software).
- Reconstructed volume evaluation
- Identification of individual nanoparticles, thresholding strategies to extract measurands (size, shape, volume) and evaluation of reconstructed volumes.
- Expression of results and uncertainty
- Guidance on extracting parameters for well-separated objects, constructing an uncertainty budget and identifying error sources, including sample representativeness, 2D projection limitations, instrument calibration, alignment and reconstruction artefacts.
- Informative case studies and annexes
- Practical examples (metal and organic nanoparticles), microscope data-collection parameters, reconstruction method comparisons and uncertainty examples.
Applications and users
ISO/TS 22292:2021 is intended for:
- Nanomaterials researchers and TEM facility staff performing electron tomography.
- Metrology and quality‑control laboratories validating nanoparticle size and shape.
- Manufacturers of nanomaterials and nanoscale devices requiring site‑specific 3D characterization.
- Instrument and software developers working on TEM/STEM tomography workflows.
Typical applications include detailed nanoparticle morphology analysis, validation of nanoscale reference materials, calibration of nanoscale measurement tools, and buried-interface characterization.
Related standards
Relevant referenced documents include:
- ISO 21363 - particle size and shape by TEM
- ISO/TS 80004 series - nanotechnology vocabulary
- ISO/IEC Guide 99 - metrology vocabulary
These provide complementary terminology, measurement vocabularies and TEM characterization methods aligned with ISO/TS 22292:2021.
Keywords: ISO TS 22292:2021, TEM tomography, 3D image reconstruction, rod-supported nano-objects, nanoparticle characterization, nanoscale metrology, STEM.