Some of the most important particles in modern industry are far too small to see, let alone measure with ordinary tools. Engineered nanoparticles, semiconductor cleanroom contaminants, and atmospheric aerosols all sit in a size range where measurement has to be precise and method-driven. ISO 15900 is the international standard that defines how that measurement is done.
This page explains what ISO 15900 is, how the method works, where it is used, and how TNV Inspection Division supports work that relies on it. TNV is a UAF accredited inspection body operating under ISO/IEC 17020:2012.
What Is ISO 15900?
ISO 15900 is the international standard titled Determination of particle size distribution — Differential electrical mobility analysis for aerosol particles. It sets out how to determine the size distribution of aerosol particles by analysing their electrical mobility, for particles roughly between 1 nm and 1 µm.
It is a method standard. It does not dictate a specific instrument design or the requirements for any one application; instead it defines the analytical approach and, importantly, the method for calculating measurement uncertainty.
How the Method Works
The standard describes a complete measurement system and gives its parts defined names:
- DMAS (differential mobility analysing system) — the complete system for carrying out the analysis.
- DEMC (differential electrical mobility classifier) — the element within the system that sorts particles according to their electrical mobility.
In simple terms, particles are given an electrical charge and then separated by how they move in an electric field, which depends on their size. From that, the system builds a size distribution. Because the method also covers uncertainty calculation, results come with a defensible measure of how reliable they are.
Where ISO 15900 Is Used
Differential electrical mobility analysis is used wherever very small airborne particles need to be measured accurately, including:
- Semiconductor manufacturing — contamination control in cleanrooms.
- Nanomaterials — characterising engineered nanoparticles.
- Aerosol instrumentation — calibrating and verifying measurement equipment.
- Atmospheric science — studying airborne particles and air quality.
- Materials produced from aerosols — controlling particle size in production.
How TNV Uses ISO 15900 as the Reference Standard
For work involving aerosol particle measurement, ISO 15900 is the reference for how that measurement should be carried out. As a UAF accredited inspection body under ISO/IEC 17020, we use the method defined in the standard as the benchmark when we inspect or verify measurement processes, systems, and the way results are produced and reported.
It is worth being precise about the boundary. Performing the laboratory measurement itself sits in testing-laboratory territory, which is governed by ISO/IEC 17025. Our role as an inspection body is to provide independent inspection, witnessing, and verification around that work: confirming that processes and equipment are being operated in line with ISO 15900, and that results and uncertainty are handled correctly. Where formal laboratory accreditation or testing is what you need, we will tell you so and point you to the right kind of body.
How We Inspect and Verify Against ISO 15900
Our work follows the method defined in the standard. In practice, an ISO 15900-related inspection by TNV can include the following.
- Process and method review. We check that the measurement procedure follows ISO 15900, including how the DMAS is set up and operated.
- Equipment verification. We confirm that the classifier and supporting equipment are suitable, maintained, and used correctly, with records to support it.
- Witnessing measurements. Where required, we witness measurements being performed to confirm they follow the defined method.
- Results and uncertainty review. We check that size distributions are calculated and that uncertainty is determined and reported as the standard requires.
- We confirm that records are complete, consistent, and traceable.
Our inspectors record observations with evidence and keep you informed throughout. The deliverable is a clear inspection report setting out what was checked, what conforms to ISO 15900, any gaps, and practical recommendations.
Our UAF Accreditation Explained
TNV Global Limited (TNV) is accredited by the United Accreditation Foundation (UAF) for inspection, under ISO/IEC 17020:2012 – Conformity assessment – Requirements for bodies providing various types of inspection. We hold that accreditation now, and we keep it through regular surveillance and witnessed inspections.
UAF is a signatory of the IAF MLA and the APAC MRA, the international recognition arrangements that let a report carry weight outside the country it was written in, and our accreditation covers work across most of Europe, the Americas, the Middle East, Africa, and Asia.
What Our Accreditation Means for You
Your inspection reports are accepted across borders, which matters in sectors like semiconductors and nanomaterials that operate globally. You get real independence, because ISO/IEC 17020 keeps us impartial and clear of any tie to the parties we inspect. And the scope and method of every inspection are set out before we start.
Who Should Use ISO 15900?
- Laboratories and facilities measuring aerosol or nanoparticle size distribution.
- Semiconductor manufacturers managing cleanroom contamination.
- Nanomaterial producers characterising their materials.
- Instrument makers calibrating and verifying aerosol measurement equipment.
- Researchers and quality teams who rely on defensible particle-size data.
How to Arrange an ISO 15900 Inspection with TNV
- Share your requirement. Reach us by website, email, phone, or WhatsApp and tell us about the process, equipment, or measurement you need inspected or verified. We review the scope against ISO 15900 and send a clear proposal covering method, timeline, and cost.
- We plan the inspection. We review the relevant procedures and records, build the inspection plan around the method, and assign inspectors with the right technical background.
- We inspect or witness. We carry out the inspection described above and record findings with evidence.
- We report. You receive the detailed inspection report within the agreed timeframe.
- We follow up. We answer questions, help you act on the findings, and point you to a testing laboratory or accreditation route where formal measurement or lab accreditation is what you need.
Why Choose TNV Inspection Division?
TNV Inspection Division is an independent, UAF accredited inspection body working under ISO/IEC 17020:2012. Independence, impartiality, and technical rigour are built into how we operate. You get an outside party with recognized accreditation, technically capable inspectors, and reports you can rely on, plus honest guidance on where inspection ends and laboratory testing begins.
Frequently Asked Questions(FAQ)
Talk to TNV Inspection Division
Need independent inspection or verification of aerosol particle-size measurement against ISO 15900? Contact TNV Inspection Division for a clear scope and a free quote.