Calibration methodology, instrument validation, and case studies from continuous particulate-matter monitoring in heavy industry, by the Arpuro Labs engineering team.https://blog.arpuro.io/enhttps://blog.arpuro.io/blog/diffuse-emissions-pm-and-industry-4-0-a-wry-look-at-development-of-sota-2019-2026/https://blog.arpuro.io/blog/diffuse-emissions-pm-and-industry-4-0-a-wry-look-at-development-of-sota-2019-2026/In this post I provide a BTS perspective on development of SOTA for PM measurements 2019-2026, based on experiences from a number of R&D projects. This is done on the backdrop of the 2023 report by NEA and Norce about "Monitoring of diffuse emissions to air from industry".Fri, 19 Jun 2026 11:37:00 GMTGrim Gjønneshttps://blog.arpuro.io/blog/arpuro-labs-employee-owned/https://blog.arpuro.io/blog/arpuro-labs-employee-owned/Arpuro Labs is now wholly owned by the engineers who built the dust-monitoring platform at Signal Analysis Lab. The new structure dedicates the company entirely to industrial particulate-matter monitoring.Tue, 19 May 2026 09:00:00 GMTannouncementcompanyownershiphttps://blog.arpuro.io/blog/arpuro-labs-pa-industriuka-2026/https://blog.arpuro.io/blog/arpuro-labs-pa-industriuka-2026/1-4. juni er det Industriuka 2026 i Porsgrunn. Grim er der med Arpuro støvsensorer i bag'en; kontakt ham på grimg@crispideas.com eller +47 934 01 002 for uformell demo.Fri, 15 May 2026 11:44:00 GMTGrim Gjønneshttps://blog.arpuro.io/blog/genai-roi-dust-monitoring-2026/https://blog.arpuro.io/blog/genai-roi-dust-monitoring-2026/Grim Gjønnes pushes back on the MIT finding that 95% of organisations see no ROI from generative AI. Using Arpuro's dust-monitoring deployments as case studies, he sketches concrete returns in heavy industry: cleaning costs, avoided failures, smarter capex.Fri, 03 Apr 2026 00:00:00 GMTgenerative-airoidust-monitoringmetallurgyindustryGrim Gjønneshttps://blog.arpuro.io/blog/ntva-ki-prosessindustri-svevestov-2026/https://blog.arpuro.io/blog/ntva-ki-prosessindustri-svevestov-2026/NTVA-arrangement i Grimstad. Gunnar Hansen (Elkem IT) snakker om hvordan KI skaper verdi i prosessindustrien, og Geir Kulia (Signal Analysis Lab) presenterer et sanntids svevestøvmåleinstrument utviklet sammen med Elkem.Tue, 24 Feb 2026 16:00:00 GMThttps://blog.arpuro.io/blog/guest-lecture-in-ttk4240-dust-sensing-from-photons-to-data/https://blog.arpuro.io/blog/guest-lecture-in-ttk4240-dust-sensing-from-photons-to-data/Guest lecture at NTNU – "Dust Sensing: From Photons to Data." Light scattering, the optical particle counter signal chain, and lessons from taking Arpuro from prototype to production. Fri, 30 Jan 2026 23:48:00 GMThttps://blog.arpuro.io/blog/elektronikknett-arpuro-sensor-accuracy-2025/https://blog.arpuro.io/blog/elektronikknett-arpuro-sensor-accuracy-2025/Arpuro PM sensor delivers ±15% accuracy with no drift after 6 months in harsh industrial sites. Site-specific calibration adapts to varied dust chemistries.Sat, 01 Nov 2025 00:00:00 GMTsensorcalibrationfield-performancehttps://blog.arpuro.io/blog/business-norway-real-time-dust-monitoring/https://blog.arpuro.io/blog/business-norway-real-time-dust-monitoring/Business Norway profiles our work on continuous particulate-matter monitoring for industrial operations — connecting worker-health protection, environmental compliance, and operational efficiency into a single instrumented platform.Wed, 08 Oct 2025 00:00:00 GMTpolicyhealth-and-safetysustainabilityhttps://blog.arpuro.io/blog/eyde-cluster-air-quality-2025/https://blog.arpuro.io/blog/eyde-cluster-air-quality-2025/The Eyde Cluster writes up our work bringing continuous air-quality data into the process industry. The piece notes the NTNU origins of the technology and support from Innovation Norway and the Research Council of Norway.Mon, 02 Jun 2025 00:00:00 GMTeydeprocess-industryfundinghttps://blog.arpuro.io/blog/shifter-asthma-to-15-factories-2025/https://blog.arpuro.io/blog/shifter-asthma-to-15-factories-2025/Shifter traces the founding story: Geir Kulia's chronic asthma as the personal motivation behind building a dust-monitoring company. The piece counts more than fifteen factory deployments and outlines plans for European expansion.Tue, 13 May 2025 00:00:00 GMTfounderscompany-historyexpansionhttps://blog.arpuro.io/blog/nrk-dagsrevyen-elkem-collaboration-2025/https://blog.arpuro.io/blog/nrk-dagsrevyen-elkem-collaboration-2025/Norway's national TV news covers our collaboration with Elkem on real-time particulate-matter sensors for furnace floors and material-handling areas — tying together air quality, worker safety, and operational decisions.Mon, 24 Mar 2025 00:00:00 GMTelkembroadcastindustrial-collaborationhttps://blog.arpuro.io/blog/nrk-sorlandet-elkem-collaboration-2025/https://blog.arpuro.io/blog/nrk-sorlandet-elkem-collaboration-2025/The regional NRK arm covers the same Elkem collaboration with a Sørlandet angle — founder background, the health motivation behind the work, and the broader environmental implications of continuous PM monitoring.Mon, 24 Mar 2025 00:00:00 GMTelkembroadcastsorlandethttps://blog.arpuro.io/blog/demystifying-the-hilbert-huang-transform-and-its-practical-applications/https://blog.arpuro.io/blog/demystifying-the-hilbert-huang-transform-and-its-practical-applications/60-min webinar on the Hilbert-Huang Transform: EMD into IMFs plus Hilbert spectral analysis for non-linear, non-stationary signals.60-min webinar on the Hilbert-Huang Transform: EMD into IMFs plus Hilbert spectral analysis for non-linear, non-stationary signals.Wed, 15 Jan 2025 16:00:00 GMTGeir Kuliahttps://blog.arpuro.io/blog/gce-node-from-automobiles-to-offshore-wind-2024/https://blog.arpuro.io/blog/gce-node-from-automobiles-to-offshore-wind-2024/A GCE Node seminar write-up exploring how diagnostics built originally for EV powertrains transfer to offshore-wind reliability — the kind of cross-domain reliability work that underpins our dust-monitoring platform.Sun, 15 Dec 2024 00:00:00 GMTgce-nodereliabilitycross-domainhttps://blog.arpuro.io/blog/shifter-emny-international-scaling-2024/https://blog.arpuro.io/blog/shifter-emny-international-scaling-2024/Shifter covers the company's participation in Innovation Norway's EMNY (Executive Marketing New York) programme — the scaling track for Norwegian startups making the jump to international markets.Sun, 15 Dec 2024 00:00:00 GMTscalinginnovation-norwayemnyhttps://blog.arpuro.io/blog/gce-node-electric-powertrain-2024/https://blog.arpuro.io/blog/gce-node-electric-powertrain-2024/Technical seminar at GCE NODE in Kristiansand on transferring advanced electric-motor technologies from automotive manufacturing to offshore energy. Co-hosted with UiS and Signal Analysis Lab.Thu, 12 Dec 2024 08:00:00 GMThttps://blog.arpuro.io/blog/order-tracking-simplified-tachometer-vs-tachometer-free-approaches/https://blog.arpuro.io/blog/order-tracking-simplified-tachometer-vs-tachometer-free-approaches/45-min webinar on order tracking for rotating machinery: tachometer-based vs.45-min webinar on order tracking for rotating machinery: tachometer-based vs. tacholess methods using instantaneous frequency estimation. Algorithms, trade-offs, and industrial cases.Sun, 10 Nov 2024 23:34:00 GMThttps://blog.arpuro.io/blog/enhancing-machine-condition-monitoring-using-order-spectrum-analysis/https://blog.arpuro.io/blog/enhancing-machine-condition-monitoring-using-order-spectrum-analysis/30-min webinar on order spectrum analysis for condition monitoring: detecting and diagnosing faults in rotating machinery, interpreting order vs. frequency spectra, and using results to guide maintenance. For engineers working with machine health and vibration data.Wed, 31 Jul 2024 22:40:00 GMTGeir Kuliahttps://blog.arpuro.io/blog/arduino-case-study-on-the-arpuro-pm-monitor/https://blog.arpuro.io/blog/arduino-case-study-on-the-arpuro-pm-monitor/Arduino's case-study series details the partnership behind our PM sensor — built on the Arduino MKR platform, with self-cleaning intake, multiple connectivity options, and a roadmap that takes the product beyond Norway.Mon, 01 Jan 2024 00:00:00 GMTarduinohardwarecase-studyhttps://blog.arpuro.io/blog/innoventus-sor-example-to-follow-2022/https://blog.arpuro.io/blog/innoventus-sor-example-to-follow-2022/Innoventus Sør writes up the company's diversity-focused organisational design work — done in collaboration with Innoventus Sør, GCE NODE, and 07 Sør — as a model for other early-stage Norwegian deeptech teams.Mon, 20 Jun 2022 00:00:00 GMTorganisationdiversityinnoventushttps://blog.arpuro.io/blog/neural-network-floating-wind-turbine-mooring-2021/https://blog.arpuro.io/blog/neural-network-floating-wind-turbine-mooring-2021/A neural-network surrogate for mooring-line tensions on the OC3-Hywind floating wind turbine. Trained on 32 wave states, it reaches ~71% correlation with the reference solver at a fraction of the runtime — useful in early-stage design and fatigue iteration.Mon, 01 Nov 2021 00:00:00 GMTneural-networksfloating-wind-turbinemooringiopGeir Kuliahttps://blog.arpuro.io/blog/passive-control-wave-energy-hilbert-huang-2017/https://blog.arpuro.io/blog/passive-control-wave-energy-hilbert-huang-2017/A passive-control strategy for wave-energy converters that adapts damping to instantaneous wave frequency rather than using static tuning. HHT supplies the frequency at every sample; the adaptive controller improves energy absorption over fixed-gain in irregular seas.Mon, 09 Oct 2017 00:00:00 GMThilbert-huangwave-energycontrolifacGeir Kuliahttps://blog.arpuro.io/blog/hilbert-huang-vs-wavelet-instantaneous-frequency-2017/https://blog.arpuro.io/blog/hilbert-huang-vs-wavelet-instantaneous-frequency-2017/A head-to-head between the Hilbert–Huang transform and discrete wavelet decomposition for instantaneous frequency in non-stationary signals. Tests on synthetic data and real EEG recordings show HHT yielding more interpretable oscillatory components.Mon, 18 Sep 2017 00:00:00 GMThilbert-huangwaveletinstantaneous-frequencyitiseeegGeir Kuliahttps://blog.arpuro.io/blog/harmonics-propagation-microgrids-2017/https://blog.arpuro.io/blog/harmonics-propagation-microgrids-2017/How harmonics cycle between the AC and DC sides of a single-phase PV inverter in islanded operation: feed-forward injects even harmonics on the DC bus; feedback re-injects them as odd AC harmonics. The paper isolates and predicts the self-sustaining pattern.Wed, 28 Jun 2017 12:00:00 GMTharmonicsmicrogridsphotovoltaiciccepGeir Kuliahttps://blog.arpuro.io/blog/time-varying-frequency-power-components-2017/https://blog.arpuro.io/blog/time-varying-frequency-power-components-2017/When grid frequency drifts, the textbook active/reactive split of instantaneous power misattributes oscillatory terms. Keeps the decomposition coherent under a time-varying angular frequency, with stand-alone power-system field data as the validation case.Wed, 28 Jun 2017 00:00:00 GMTpower-systemsmicrogridsinstantaneous-powericcepGeir Kuliahttps://blog.arpuro.io/blog/ntb-studentgrunder-million-2016/https://blog.arpuro.io/blog/ntb-studentgrunder-million-2016/NTB covers the Research Council of Norway's StudENT-programme grants — including a NOK 1 million award that bridged the team's transition from a university project to a real business. The earliest piece of coverage in this archive.Thu, 22 Dec 2016 00:00:00 GMTntbstudentgrunderforskningsradethttps://blog.arpuro.io/blog/real-time-measurement-platform-microgrids-2016/https://blog.arpuro.io/blog/real-time-measurement-platform-microgrids-2016/A real-time measurement framework that uses empirical-mode decomposition to extract instantaneous frequency and amplitude from microgrid voltage and current. The grid-connected vs standalone comparison confirms isolated systems are fundamentally more non-stationary.Thu, 01 Dec 2016 00:00:00 GMTmicrogridsempirical-mode-decompositionmeasurementprocediaGeir Kuliahttps://blog.arpuro.io/blog/distortions-microgrids-msc-thesis-2016/https://blog.arpuro.io/blog/distortions-microgrids-msc-thesis-2016/The MSc thesis Signal Analysis Lab (now Arpuro Labs) was built on. Examines how harmonic distortion, inverter switching artefacts, and load nonlinearities propagate in standalone microgrids — and where Hilbert–Huang reveals time-varying content Fourier flattens out.Sat, 15 Oct 2016 00:00:00 GMTmsc-thesismicrogridshilbert-huangntnufoundationGeir Kuliahttps://blog.arpuro.io/blog/detect-waveform-distortions-microgrids-2016/https://blog.arpuro.io/blog/detect-waveform-distortions-microgrids-2016/Validation of an HHT diagnostic tool against measurements from a standalone PV microgrid in Bhutan. Time-varying frequencies and amplitude-modulation patterns invisible to Fourier show up clearly in the empirical-mode decomposition.Thu, 13 Oct 2016 00:00:00 GMThilbert-huangmicrogridsvalidationghtcbhutanGeir Kuliahttps://blog.arpuro.io/blog/instantaneous-frequency-power-systems-2016/https://blog.arpuro.io/blog/instantaneous-frequency-power-systems-2016/A short technical case for treating instantaneous frequency as a fundamental observable, not a derived quantity. Surveys where Fourier and wavelet break down in microgrids and under time-varying loads, and argues for Hilbert–Huang as the right primitive.Wed, 01 Jun 2016 00:00:00 GMThilbert-huanginstantaneous-frequencypower-systemsposterntnuGeir Kuliahttps://blog.arpuro.io/blog/permutation-entropy-wind-turbine-fault-2016/https://blog.arpuro.io/blog/permutation-entropy-wind-turbine-fault-2016/Permutation entropy on phase-current measurements as a wind-turbine fault indicator. Where Fourier spectra could not separate healthy from faulty operation, the entropy of ordinal patterns did — a single scalar that tracked degradation without per-fault tuning.Fri, 22 Jan 2016 00:00:00 GMTpermutation-entropyfault-detectionwind-energypreprintarxivGeir Kulia