Scientific papers
Independent scientific publications benchmarking NextPM's particulate matter measurement performance.
Benchmarking Low-Cost Particulate Matter Sensors: Evaluating
Performance Under Controlled Environmental Conditions Using
Low-Cost Experimental Setups#
Title: Benchmarking Low-Cost Particulate Matter Sensors: Evaluating Performance Under Controlled Environmental Conditions Using Low-Cost Experimental Setups
Authors: Arianna Alvarez Cruz, Olivier Schalm, Luis Ernesto Morera Hernández, Alain Martínez Laguardia, Daniellys Alejo Sánchez, Mayra C. Morales Pérez, Rosa Amalia González Rivero, Yasser Morera Gómez
Affiliations: Central University “Marta Abreu” of Las Villas (Cuba), Antwerp Maritime Academy (Belgium), Cienfuegos Center of Environmental Studies (Cuba)
Project: Comparative assessment of low-cost PM sensors (NextPM vs OPC-N3) under laboratory and tropical field conditions
Publisher: Atmosphere – MDPI, Basel, Switzerland (peer-reviewed journal)
Date: February 2025
Document Type: Peer-reviewed scientific article (open access, 22 pages)
DOI / URL: https://doi.org/10.3390/atmos16020172
This study benchmarked two low-cost particulate matter sensors—the Alphasense OPC-N3 and Tera Sensor’s NextPM—through controlled lab experiments (clean air and water aerosols) and a 27-day field deployment in Cienfuegos, Cuba. The aim was to assess their stability, noise, humidity sensitivity, and reliability using raw data only, without post-processing or external calibration.
The NextPM sensor demonstrated superior performance with 80% noise reduction in clean-air tests (PM₂.₅: 0.3 ± 0.2 µg/m³ vs. OPC-N3: 0.4 ± 0.5 µg/m³) and fewer outliers (79 vs. 87 for PM₁₀). In water aerosol tests, it recorded a max PM₁₀ of 11.3 µg/m³, compared to 103.3 µg/m³ for the OPC-N3, showing stronger rejection of liquid aerosols. In the field, NextPM’s PM₂.₅ average was slightly higher (6.4 µg/m³ vs. 4.5 µg/m³), but with half the variability for PM₁₀ (standard deviation: 5.6 vs. 12.1 µg/m³), and fewer extreme values, highlighting its resistance to humidity-induced drift thanks to its built-in heater
AQSPEC 2021 LAB EVALUATION#
Title: Laboratory Evaluation – Tera Sensor NextPM
Authors: South Coast Air Quality Management District (AQMD)
Organization: AQ-SPEC (Air Quality Sensor Performance Evaluation Center)
Date: Report not explicitly dated, but based on tests conducted from September to November 2021 (and published after March 2022)
Publisher Location: South Coast AQMD, Diamond Bar, CA, USA
URL (reference page): https://www.aqmd.gov/aq-spec/sensors\
Document Type: Technical laboratory evaluation report
This study was conducted by the AQ-SPEC lab at South Coast AQMD to evaluate the performance of two NextPM sensors under controlled laboratory conditions for PM₂.₅ and PM₁₀ measurements, following an initial field test phase. Results show outstanding correlation with reference-grade instruments (R² > 0.99), high and stable precision, 100% data recovery, and strong resistance to temperature and humidity changes, although the sensor consistently underestimates absolute concentrations compared to FEM standards.
AQSPEC 2021 FIELD EVALUATION#
Title: Field Evaluation – Tera Sensor NextPM
Authors: South Coast Air Quality Management District (AQMD)
Organization: AQ-SPEC (Air Quality Sensor Performance Evaluation Center)
Date: Based on field deployment between September 29 and November 28, 2021
Publisher Location: South Coast AQMD, Diamond Bar, CA, USA
URL (reference page): https://www.aqmd.gov/aq-spec/sensors\
Document Type: Field evaluation technical report (preliminary results)
This field evaluation by the South Coast AQMD assessed the performance of three NextPM sensors over two months under real ambient conditions at the Rubidoux monitoring station, in comparison with reference-grade instruments such as the GRIMM and Teledyne T640. The NextPM sensors demonstrated strong to very strong correlations for PM₁.0 and PM₂.₅ (R² > 0.95 on 24-hour averages), high data recovery (~96%), and excellent inter-unit consistency, although they systematically underestimated concentrations, especially for PM₁₀ where correlation dropped to moderate levels (R² ~ 0.65).
LCE - In Field Study of NextPM Sensor #
Title: In-Field Study of NextPM Sensor
Authors: H. Wortham, L. Le Berre, R. Berdouni, C. Benadda, C. Chikhi, M. Mezzanotti
Reference: RR-20210112-01
Version: 1.0
Date: February 22, 2021
Affiliations: AtmoSud (Air Quality Monitoring Network, PACA region, France) and Laboratoire de Chimie de l’Environnement (LCE), Aix-Marseille University
Location: Longchamp Super-site, Marseille, France
Document Type: Scientific evaluation report (preliminary phase of a one-year field study)
This field study, conducted at the highly instrumented Longchamp “super-site” in Marseille by AtmoSud and Aix-Marseille University, aimed to assess the performance of the NextPM sensor under real-world conditions, focusing on its ability to operate accurately across varied humidity, aerosol types, and meteorological scenarios. Results show very high correlation with a certified reference instrument for PM₁ and PM₂.₅ (R² up to 0.93 daily, 0.86 hourly), a 100% data recovery rate, excellent sensor reproducibility, and real-time capabilities nearly matching those of a regulatory analyzer—while PM₁₀ correlations were lower and more variable, likely due to particle dynamics and airflow limitations.
REAL-TIME POLLUTANT IDENTIFICATION THROUGH OPTICAL
PM MICRO-SENSOR#
Title: Real-Time Pollutant Identification through Optical PM Micro-Sensor
Authors: Elie Azeraf, Audrey Wagner, Emilie Bialic, Samia Mellah, Ludovic Lelandais
Affiliation: Capgemini Engineering
Status: Preprint on arXiv (arXiv:2503.10724v1)
Date: March 13, 2025
Corresponding Author: elie.azeraf@capgemini.com
Document Type: Scientific preprint (submitted to arXiv)
Link: https://arxiv.org/abs/2503.10724
This study by Capgemini Engineering explores the use of machine learning (ML) techniques to identify specific pollution sources in real time—such as sand, ash, or candle smoke—using only data from the NextPS optical micro-sensor developed by Tera Sensor. By leveraging a novel classification framework based on particle size distribution ratios (rather than mass), the authors demonstrate that even a low-cost OEM sensor can enable pollutant discrimination with up to 82.44% accuracy, particularly when coupled with Hidden Markov Chain models, confirming the technical robustness of the Tera sensor platform for embedded AI air quality applications.
Portable Sensors for Dynamic Exposure Assessments in Urban Environments: State of the Science#
Title: Portable Sensors for Dynamic Exposure Assessments in Urban Environments: State of the Science
Authors: Jelle Hofman, Borislav Lazarov, Christophe Stroobants, Evelyne Elst, Inge Smets, Martine Van Poppel
Affiliations: VITO – Environmental Intelligence Unit; Flanders Environmental Agency (VMM), Belgium
Journal: Sensors, MDPI (ISSN 1424-8220)
Volume & Issue: Vol. 22, No. 14, Article 5472
Date: July 2022
DOI: https://doi.org/10.3390/s22145472\
Document Type: Peer-reviewed scientific journal article
As part of a comparative evaluation of 10 portable air quality sensors, the study tested the PMSCAN device from Tera Sensor, which integrates the NextPM optical sensor, for its ability to measure PM₂.₅ and PM₁₀ in mobile, urban conditions. The PMSCAN exhibited a good correlation with reference measurements for PM₂.₅ (R² up to 0.88), and was praised for its high measurement resolution and robustness, although like most sensors in the comparison, it required post-processing to correct for environmental influences such as humidity.