About this directory
Scope, sources and curation methods for the light logger validation directory.
Literature checked 10 November 2026 · 28 studies · 29 device entries · 26 peer reviewed · 2 preprints · 0 conference paper
Reading the directory
Each square represents one validation study for that device. Orange hatching marks documented developer involvement. The Device outputs columns show confirmed photopic illuminance and melanopic EDI features. Separate Examined in studies columns show whether the listed studies test photopic illuminance, melanopic EDI or angle dependence. Output checks remain fixed when filtering; examination checks follow the matching studies. Counts are not accuracy ratings.
Manufacturers and research developers group related models. Results remain specific to each tested model. “Commercial model” and “Research device” describe the instruments in the cited literature, rather than current purchasing availability.
Output capability and validation are stored separately, with literature sources. A dash means capability has not been established in the inspected sources. Checked independent authorship is noted in study details; unhighlighted squares do not imply independence.
Scope
This directory includes primary studies with extracted direct tests of photopic illuminance, melanopic EDI or angle dependence. Indoor/outdoor and light-source classification papers are excluded unless the paper separately tests one of those three measurements. Placement-only, spectral-only, dose-only and other-endpoint papers are outside this scope. The expanded search is documented below. It is not an exhaustive systematic review: some known candidates still need extraction, and the search can miss relevant work.
Development papers are included when they report measurement tests. Each entry states the evidence type, reference, source access and limits. Inclusion does not certify a device. Reference comparisons, between-device agreement, repeatability and wearing-position studies are labelled separately; they do not provide interchangeable evidence of absolute accuracy.
Sources are research publications and explicitly labelled preprints. Manufacturer specifications and marketing claims are not used as validation evidence. Studies concerned only with sleep, activity, or physiological outcomes do not establish the accuracy of a device’s light sensor and are outside this collection’s measurement scope.
Literature search
On 10 November 2026, three Europe PMC queries returned 751 records, or 733 unique database accessions. A title prefilter retained 361 titles for inspection. Selected candidates were then checked against primary abstracts or full texts. Named-device searches, publisher and institutional records, and backward citation checking supplemented these queries.
The directory contains 28 papers. 5 currently rely on abstracts; 1 uses a partial full-text passage. The included-paper count is not the number of search hits screened, and does not imply exhaustive coverage.
Exact database queries and counts
391 records, all retrieved. Saved response
TITLE_ABS:((Actiwatch OR ActTrust OR GENEActiv OR MotionWatch OR HOBO OR ActiGraph) AND (light OR illuminance OR photometric) AND (validat* OR calibrat* OR accuracy OR spectral OR agreement OR characteri*)) AND FIRST_PDATE:[1900-01-01 TO 2026-11-10]
306 records, all retrieved. Saved response
TITLE:((light OR illuminance OR photometric OR melanopic) AND (dosimeter OR logger OR wearable OR wrist OR sensor OR monitor)) AND TITLE_ABS:(validat* OR calibrat* OR accuracy OR characteri*) AND FIRST_PDATE:[1900-01-01 TO 2026-11-10]
54 records, all retrieved. Saved response
TITLE_ABS:(Clouclip OR MyLyt OR Daysimeter OR Spectrace OR SpectraWear OR ActLumus OR OcuWEAR OR "LYS Button" OR (Kronowise AND light)) AND FIRST_PDATE:[1900-01-01 TO 2026-11-10]
Europe PMC includes PubMed/MEDLINE and indexed preprints. Search results were deduplicated by database source and accession; the included inventory has unique DOIs. The title prefilter, per-title dispositions and source-check decisions are available below. Records omitted by that prefilter were not manually screened. Three broader pilot searches were capped at 1,000 results each and are excluded from these counts.
Citation checking used the V3 framework, a 2025 light-device survey, the myopia light-meter review, and references in primary papers. Reviews helped identify sources; their device specifications were not treated as validation results.
Limitations include English search terms, the title prefilter, no subscription-database search, indexing delays, incomplete access to older papers, and no independent second screening. Theses and conference abstracts have not been comprehensively assessed. A missing entry does not mean that a device has no validation evidence.
Search audit (JSON) · Title triage (CSV) · Source decisions (CSV)
Other candidates, unresolved papers and scope decisions
Awaiting full-text check. Application paper may contain device calibration checks; abstract does not resolve whether it adds original performance data.
Source checked: Abstract / citation chain
Awaiting full-text check. HOBO application; determine whether original calibration or classifier testing is reported.
Source checked: Citation / abstract
Awaiting supplement check. LightWatcher calibration supplement may add relevant sensor tests; treatment outcome findings alone are outside scope.
Source checked: Citation chain / supplement description
Awaiting calibration extraction. Main comparison evaluates satellite estimates. Determine whether LightWatcher stability/calibration data justify a separate hardware record.
Source checked: Primary study description / indexed passages
Awaiting full-text check. Proceedings report of ocular visible-light sensing; quantitative performance and reference instrument not yet extracted.
Source checked: Publisher metadata
Awaiting full-text check. Abstract validates activity and sleep components and describes environmental spectra; it does not establish an independent light-measurement reference test.
Source checked: PubMed abstract
Awaiting full-text check. Check for original position or reference-instrument comparison before assigning sensor-validation endpoints.
Source checked: Citation chain
Limited measurement report. Results state that readings were of the same order of magnitude as an in-house meter, but give no quantitative accuracy test or reference model. Usability and wear-time outcomes are not light-sensor validation.
Source checked: Full text: Methods and Results
Application / no extracted sensor validation. HOBO exposure profiles and questionnaire/environmental context; no independent quantitative sensor calibration identified in the inspected text.
Source checked: Full text
Clinical association / related application. Clinical symptom association is not independent light-sensor accuracy. Hardware platform development is represented by Heo and Kwon.
Source checked: Full text / abstract
Application / abstract inconclusive. Accessible abstract describes occupational exposure patterns without an independent light-measurement validation. Full text could contain additional technical checks.
Source checked: PubMed abstract
Related sampling methods. Sampling-duration reliability concerns exposure summaries; not a standalone absolute sensor-accuracy test.
Source checked: Citation / abstract
Related simulation methods. Uses body geometry and simulated illumination; no measured wearable-hardware validation.
Source checked: Full text
Related simulation methods. Body scans and simulated placement/occlusion effects; not a separate empirical sensor-validation dataset.
Source checked: Full text
Related adherence methods. Validates nonwear detection rather than light-measurement accuracy. Preprint 10.1101/2025.09.29.25336898 is not counted again.
Source checked: Indexed journal record / abstract
Outside wearable scope. Stationary environmental light sensor network rather than wearable personal dosimetry.
Source checked: Full text
Cole et al. (1990). Ambulatory monitoring of light exposure: comparison of measurements at forehead and wrist
Limited report; not yet extracted. Sleep Research 19:364 conference abstract found through citations; primary abstract and device details not retrieved.
Source checked: Secondary citation only
Limited report; not yet extracted. Conference abstract within Clocks & Sleep 8(1):2; ActTrust2. Not a full validation paper.
Source checked: Conference abstract listing
Nishanth et al. (2022). Accurate Measurement of Outdoor Activities in Children with Myopia: Development of an Affordable Wearable Device
Limited report; not yet extracted. IOVS 63(7):2144–A0172 meeting abstract; determine overlap with subsequent full papers before counting independently.
Source checked: Citation chain
Hubalek (2007). Light measurement / LuxBlick doctoral thesis
Thesis not yet assessed. Original thesis may contain validation data; eligibility and overlap with journal publications remain unresolved.
Source checked: Review bibliography
Moafa (2019). Quantifying Risk Factors for Myopia: Instrument Validation and Establishing Dosage for Light Intensity and Duration
Thesis not yet assessed. Thesis may contain additional validation experiments; full-text extraction and publication-overlap assessment remain open.
Source checked: Review bibliography
Philips (2008). Characterization of Light Sensor Performance for Three Models of Actiwatch
Manufacturer material excluded. Manufacturer white paper, not an indexed research publication in the present literature-only collection.
Source checked: Citation chain
Excluded by curator. Removed from the directory at the curator’s request on 10 November 2026.
Source checked: Abstract
Outside narrowed scope. No extracted direct test of photopic illuminance, melanopic EDI or angle dependence. Classification-only and other-endpoint records are excluded from this directory.
Source checked: Abstract
Outside narrowed scope. No extracted direct test of photopic illuminance, melanopic EDI or angle dependence. Classification-only and other-endpoint records are excluded from this directory.
Source checked: Full text
Outside narrowed scope. No extracted direct test of photopic illuminance, melanopic EDI or angle dependence. Classification-only and other-endpoint records are excluded from this directory.
Source checked: Full text
Outside narrowed scope. No extracted direct test of photopic illuminance, melanopic EDI or angle dependence. Classification-only and other-endpoint records are excluded from this directory.
Source checked: Full text
Outside narrowed scope. No extracted direct test of photopic illuminance, melanopic EDI or angle dependence. Classification-only and other-endpoint records are excluded from this directory.
Source checked: Full text
Outside narrowed scope. No extracted direct test of photopic illuminance, melanopic EDI or angle dependence. Classification-only and other-endpoint records are excluded from this directory.
Source checked: Full text
Outside narrowed scope. No extracted direct test of photopic illuminance, melanopic EDI or angle dependence. Classification-only and other-endpoint records are excluded from this directory.
Source checked: Full text
Outside narrowed scope. No extracted direct test of photopic illuminance, melanopic EDI or angle dependence. Classification-only and other-endpoint records are excluded from this directory.
Source checked: Full text
Outside narrowed scope. No extracted direct test of photopic illuminance, melanopic EDI or angle dependence. Classification-only and other-endpoint records are excluded from this directory.
Source checked: Full text
Outside narrowed scope. No extracted direct test of photopic illuminance, melanopic EDI or angle dependence. Classification-only and other-endpoint records are excluded from this directory.
Source checked: Abstract
Outside narrowed scope. No extracted direct test of photopic illuminance, melanopic EDI or angle dependence. Classification-only and other-endpoint records are excluded from this directory.
Source checked: Abstract
Outside narrowed scope. No extracted direct test of photopic illuminance, melanopic EDI or angle dependence. Classification-only and other-endpoint records are excluded from this directory.
Source checked: Abstract
Excluded by curator. Anonymised device models cannot support lookup of identifiable light loggers; removed at the curator’s request.
Source checked: Full text
Outside narrowed scope. Placement-only study excluded at the curator’s request; direct device-performance studies remain.
Source checked: Full text
Outside narrowed scope. Placement-only study excluded at the curator’s request; direct device-performance studies remain.
Source checked: Full text
Outside narrowed scope. Placement-only study excluded at the curator’s request; direct device-performance studies remain.
Source checked: Abstract
Excluded by curator. Unnamed hospital logger removed at the curator’s request; its model cannot be identified.
Source checked: Abstract
How to read an entry
- Device model. Evidence applies to the model named in the paper. Related models and later hardware or firmware versions may perform differently.
- Tested measurement. Photopic illuminance, melanopic quantities, spectral response, angular response, and other endpoints answer different questions. Outdoor classification concerns identifying environments rather than absolute illuminance accuracy. Tests of one endpoint do not establish accuracy for another.
- Conditions. Reference instruments, light sources, intensity ranges, sensor orientation, and body position affect how results can be used.
- Publication and source access. Preprints may not have undergone peer review. Abstract-only records provide less methodological detail than full-text records.
- Study counts. Counts describe the papers included here. No cross-study accuracy ranking or pooled estimate is calculated.
Device names. LYS and LYS Button are one device entry; the name used in each paper is retained where relevant. Other unresolved versions remain explicitly labelled. “Device entries” includes prototypes, unnamed models and one group of seven anonymised dosimeters; it is not a count of distinct commercial models.
Publication images. Journal and preprint-server marks identify sources. Where a journal-specific asset was unavailable, a publisher logo or the journal’s name is used. Covers identify the venue, not necessarily the paper’s issue. Device images are not shown.
Curation and updates
Records contain a citation, persistent source link, tested device names, measurement categories, setting, reference, protocol summary, findings, limitations, and a locator for the supporting source passage, table or figure. Device-specific endpoint mappings prevent tests reported for one model from being assigned to every model in the same paper. Summaries are brief paraphrases; consult the original paper for numerical results, uncertainty, and complete methods. A paper may include several devices, so study counts and device counts are different units.
Publication years. Years follow the checked research records. Some use journal issue year and some online-first year; discrepancies are identified in each record’s notes. Publication year is not the date of testing.
Use Submit a validation on the directory to suggest a paper. A curator should check the source, model, methods, review status and conclusions before adding it. Submissions are not added automatically. New versions of a preprint should update the existing record rather than be counted as independent studies.
Reproduce and reuse
The website and this notebook read the same versioned JSON inventory. Rendering the directory notebook rebuilds the interface and downloadable records; this notebook regenerates the provenance inventory below. The build does not query websites or change the literature records. Search and filters run in the visitor’s browser.
The CSV preserves the study summaries and device-specific endpoint mappings. The BibTeX export contains partial citation metadata: title, DOI, URL and the indexed year. Abbreviated display authors are preserved in the note field rather than represented as a complete author list. Resolve the DOI for complete author, journal and publication-date metadata before using the export in a manuscript.
Download the study table (CSV) · Download citations (BibTeX) · Download this notebook
Study inventory
Gemici et al. · 2026 · Preprint
-
Journal / server
-
arXiv
-
Devices
-
ActTrust2; ActLumus
-
Measurements
-
Illuminance; Melanopic EDI
-
Device-specific coverage
-
ActTrust2: Illuminance | ActLumus: Illuminance, Melanopic EDI
-
Setting
-
Field
-
Evidence type
-
Reference comparison
-
Reference
-
JETI Spectraval 1501 in Tübingen; Konica Minolta CL-500A in Izmir.
-
Protocol
-
Fixed tripod rig sampled 433 indoor/outdoor scenes across daylight, artificial and mixed lighting in Tübingen and Izmir. Bootstrap resampling assessed sampling requirements.
-
Reported findings
-
High association with reference measurements coexisted with systematic underestimation. Bias depended on the lighting condition and scene characteristics. Performance estimates stabilized at approximately 100 sampled scenes in this dataset.
-
Limits of interpretation
-
Preprint. Tripod measurements do not establish continuous on-body accuracy. Only one ActTrust2 unit and two ActLumus units were tested, with one ActLumus at each site.
-
Source inspected
-
Full text
-
Evidence location
-
PDF pp. 6–7: Measurement setup; pp. 11–12: Results; Figure 2: A ActLumus mEDI, B ActLumus illuminance, C ActTrust2 illuminance.
-
Curation note
-
arXiv v1, 16 June 2026. Both devices measured photopic illuminance; only ActLumus measured melanopic EDI. The same ActTrust2 unit was used at both sites.
DOI: 10.48550/arXiv.2606.20719
Kore et al. · 2026 · Peer reviewed
-
Journal / server
-
npj Biological Timing and Sleep
-
Devices
-
LYS Button; Blue Iris Speck v1.0; Actiwatch Spectrum Plus
-
Measurements
-
Angular response; Illuminance; Melanopic EDI
-
Device-specific coverage
-
LYS Button: Illuminance, Melanopic EDI, Angular response | Blue Iris Speck v1.0: Illuminance, Melanopic EDI, Angular response | Actiwatch Spectrum Plus: Illuminance, Angular response
-
Setting
-
Laboratory + field
-
Evidence type
-
Characterisation
-
Reference
-
Calibrated Gigahertz-Optik BTS256 spectroradiometer; cosine-law angular benchmark.
-
Protocol
-
Three units per model tested under controlled LEDs (0–570 lx) and partly cloudy daylight (42,000–78,000 lx), with separate angular and temperature tests.
-
Reported findings
-
Speck showed the strongest overall measurement agreement in this comparison. LYS Button overestimated low-light melanopic EDI. Actiwatch had substantial photometric variability. All models showed difficulties under high daylight levels.
-
Limits of interpretation
-
Three units per type; one short daylight session; spectral reconstruction evaluated for only one Speck; no on-body position or occlusion testing. Daylight variability limits interpretation as a strict linearity test.
-
Source inspected
-
Full text
-
Evidence location
-
Results: Figures 2–3 (illuminance), 4–5 (Speck spectrum), 6 (melanopic EDI), 7 (angular response); Temperature dependence; Discussion limitations.
-
Curation note
-
Published 21 July 2026. Results concern Speck v1.0, not v2.0. Melanopic EDI was evaluated only for LYS Button and Speck under LEDs; Actiwatch was excluded because it lacks melanopic outputs. Spectral reconstruction testing applies only to Speck.
DOI: 10.1038/s44323-026-00088-y
PubMed record ↗
Pilehchi-Ha et al. · 2026 · Preprint
-
Journal / server
-
medRxiv
-
Devices
-
ActLumus; lido; OcuWEAR
-
Measurements
-
Illuminance; Melanopic EDI
-
Device-specific coverage
-
ActLumus: Illuminance, Melanopic EDI | lido: Illuminance, Melanopic EDI | OcuWEAR: Illuminance, Melanopic EDI
-
Setting
-
Laboratory + field
-
Evidence type
-
Reference comparison
-
Reference
-
Gigahertz-Optik CSS-45 reference spectroradiometer.
-
Protocol
-
Comparison under fluorescent, incandescent and multiple LED sources, plus dynamic daylight exposure.
-
Reported findings
-
Performance depended on both the source spectrum and output metric. Illuminance varied less than melanopic EDI and colour temperature. Bias under dim conditions could change exposure-threshold classification.
-
Limits of interpretation
-
Preprint. Bias varies with spectrum and metric; not every device was tested in every source condition. No universal accuracy bound or general ranking follows from these comparisons.
-
Source inspected
-
Full text
-
Evidence location
-
Methods and device-specific illuminance, melanopic EDI and CCT comparisons; CCT reported only for lido and OcuWEAR.
-
Curation note
-
CCT performance is indexed only for lido and OcuWEAR; it is not assigned to ActLumus.
DOI: 10.64898/2026.10.06.26364836
Sah et al. · 2026 · Peer reviewed
-
Journal / server
-
npj Biological Timing and Sleep
-
Devices
-
VEET; Clouclip (version not reported); Actiwatch (model not reported); ActLumus; GENEActiv
-
Measurements
-
Illuminance
-
Device-specific coverage
-
VEET: Illuminance | Clouclip (version not reported): Illuminance | Actiwatch (model not reported): Illuminance | ActLumus: Illuminance | GENEActiv: Illuminance
-
Setting
-
Field
-
Evidence type
-
Wearable-to-wearable comparison
-
Reference
-
Concurrent wearables and participant activity logs; no absolute illuminance reference.
-
Protocol
-
Thirty adults wore five sensors for one day; valid light data from 25 participants were compared across illumination categories and with activity logs.
-
Reported findings
-
Outdoor-photopic categories agreed well between devices, while low-light categories and activity-log estimates differed.
-
Limits of interpretation
-
Authors explicitly assess mutual agreement, not absolute validation. Anatomical position and sensor characteristics differ. Unreported model revisions remain unresolved.
-
Source inspected
-
Full text
-
Evidence location
-
Abstract; Results: Table 2; Introduction (scope); Methods: wearable sensors.
DOI: 10.1038/s44323-026-00113-0
PubMed record ↗
Ishihara et al. · 2025 · Peer reviewed
-
Journal / server
-
SLEEP
-
Devices
-
ActLumus; GENEActiv; ActiGraph wGT3X-BT; LYS Button
-
Measurements
-
Illuminance
-
Device-specific coverage
-
ActLumus: Illuminance | GENEActiv: Illuminance | ActiGraph wGT3X-BT: Illuminance | LYS Button: Illuminance
-
Setting
-
Laboratory + field
-
Evidence type
-
Reference comparison
-
Reference
-
NIST-calibrated ILT560-A spectrometer; free-living comparison between ActLumus and ActiGraph.
-
Protocol
-
Eight units per manufacturer tested under warm/cool LEDs (2–1,000 lx) and daylight (5,000–100,000 lx). Twenty-one adults wore ActLumus and ActiGraph concurrently for one week.
-
Reported findings
-
ActLumus had the widest tested response range and lowest between-unit variability. LYS showed larger melanopic errors under warm light. GENEActiv and ActiGraph underestimated illuminance; limited sensitivity and saturation produced large differences in daily exposure estimates.
-
Limits of interpretation
-
Two indoor spectra and selected daylight conditions do not cover all lighting environments. The field component compared two wrist devices without a continuously worn reference spectrometer.
-
Source inspected
-
Full text
-
Evidence location
-
Methods: Laboratory assessment; Results: Figures 2–6 and Free-living comparison (Figure 7).
-
Curation note
-
Online November 2025; February 2026 issue. Melanopic testing applies only to ActLumus and LYS. The paper uses melanopic illuminance/lux, not explicitly EDI; indexed here as Other circadian metrics. LYS hardware version is unspecified. Between-unit variability is distinct from repeatability. Additional reported endpoints: Dynamic range, Between-device variability. The LYS name is indexed under LYS Button; these are the same device, as clarified by the curator. The paper does not specify a hardware revision.
DOI: 10.1093/sleep/zsaf358
PubMed record ↗
Sarkar et al. · 2025 · Peer reviewed
-
Journal / server
-
Ophthalmic and Physiological Optics
-
Devices
-
Vivior Mark 3+; Clouclip (second generation)
-
Measurements
-
Illuminance
-
Device-specific coverage
-
Vivior Mark 3+: Illuminance | Clouclip (second generation): Illuminance
-
Setting
-
Laboratory + field
-
Evidence type
-
Reference comparison
-
Reference
-
Calibrated Konica Minolta CL-200A chroma meter for illumination; ruler for the separate distance assessment.
-
Protocol
-
Five units of each model attached to spectacles on a mannequin. Light measurements were repeated across seven indoor/outdoor locations on three days. A separate study tested viewing distance in 13 young adults.
-
Reported findings
-
Both devices tracked the luxmeter; individual differences became more variable above roughly 3,500–4,000 lx. Some bright indoor locations exceeded the 1,000-lx outdoor threshold.
-
Limits of interpretation
-
The participant component assessed viewing distance rather than light-measurement accuracy during unrestricted wear. The study did not validate melanopic or spectral outputs; sleep mode and spectacle use can affect deployment.
-
Source inspected
-
Full text
-
Evidence location
-
Methods: Study 1 and device descriptions; Results: Validation of ambient illumination measurements, Figures 6–7; Discussion (repeatability).
-
Curation note
-
Published 14 February 2025. Exact tested versions were five Vivior Mark 3+ and five second-generation Clouclip units. Agreement in photopic illuminance should not be generalized to other outputs or hardware generations. Outdoor-threshold discussion is not indexed as classification validation.
DOI: 10.1111/opo.13457
PubMed record ↗
Stevenson, Suppiah & Driller · 2025 · Peer reviewed
-
Journal / server
-
Lighting Research & Technology
-
Devices
-
LYS Button
-
Measurements
-
Illuminance
-
Device-specific coverage
-
LYS Button: Illuminance
-
Setting
-
Laboratory + field
-
Evidence type
-
Reference comparison
-
Reference
-
Factory-calibrated RS PRO RS-92 digital light meter.
-
Protocol
-
Two LYS Buttons were placed side by side with the reference for eight-hour indoor and outdoor recordings. Separate two-hour recordings assessed between-unit reliability.
-
Reported findings
-
Buttons read about 25 lx lower indoors and 82 lx higher outdoors on average. Between-unit ICCs were 0.90 indoors and 0.98 outdoors.
-
Limits of interpretation
-
Stationary, upward-facing sensors; no free-living wear test. Only illuminance was validated. Removal of outliers and the limited conditions affect interpretation.
-
Source inspected
-
Full text
-
Evidence location
-
Sections 2.1–2.3; Tables 1–2; Section 3.
-
Curation note
-
First published online 3 July 2025; journal issue dated 2026. Do not infer melanopic EDI or CCT validation from the device’s advertised outputs.
DOI: 10.1177/14771535251338582
McDowell et al. · 2024 · Peer reviewed
-
Journal / server
-
BMC Biology
-
Devices
-
SpectraWear
-
Measurements
-
Melanopic EDI
-
Device-specific coverage
-
SpectraWear: Melanopic EDI
-
Setting
-
Laboratory
-
Evidence type
-
Calibration study
-
Reference
-
Calibrated SpectroCal spectroradiometer; species-specific photoreceptor weighting functions.
-
Protocol
-
Ten-channel readings were fitted to reference measurements from 13 spectra, then tested at a wider range of irradiances. Performance was assessed for 12 domestic mammal species and humans.
-
Reported findings
-
Melanopic and rhodopic estimates performed better than short-wavelength cone estimates; limited UV sensitivity constrained some species-specific quantities.
-
Limits of interpretation
-
Bench calibration of wearable hardware, not an on-body validation. Accuracy depends on the spectra and species-specific response being estimated.
-
Source inspected
-
Full text
-
Evidence location
-
Figure 2; Methods: Light sensor calibration and validation.
DOI: 10.1186/s12915-024-02038-1
PubMed record ↗
Mohammadian et al. · 2024 · Peer reviewed
-
Journal / server
-
IEEE Internet of Things Journal
-
Devices
-
SpectraWear
-
Measurements
-
Angular response; Melanopic EDI
-
Device-specific coverage
-
SpectraWear: Melanopic EDI, Angular response
-
Setting
-
Laboratory + field
-
Evidence type
-
Characterisation + placement
-
Reference
-
SpectroCAL MKII spectroradiometer and calibrated custom spectral source.
-
Protocol
-
Thirteen ten-channel units were calibrated and tested across spectral/intensity conditions, with additional angular-response and body-location experiments.
-
Reported findings
-
Mean absolute errors in α-opic EDI were below 0.07 log lx; between-unit correlations were at least 0.99 under the reported conditions.
-
Limits of interpretation
-
Laboratory calibration and limited wear demonstrations do not establish equal performance under every real-world spectrum or placement.
-
Source inspected
-
Full text
-
Evidence location
-
Sections II-D, III-B and IV: calibration, EDI accuracy, directional response and wearing position.
-
Curation note
-
SpectraWear is the name used for this research platform in associated publications; the engineering paper describes a wrist-worn sensor node.
DOI: 10.1109/JIOT.2024.3355330
PubMed record ↗
Stampfli et al. · 2023 · Peer reviewed
-
Journal / server
-
Lighting Research & Technology
-
Devices
-
lido
-
Measurements
-
Angular response; Illuminance
-
Device-specific coverage
-
lido: Illuminance, Angular response
-
Setting
-
Laboratory + field
-
Evidence type
-
Characterisation
-
Reference
-
JETI specbos 1201 spectroradiometer; Ocean Insight STS-VIS for a real-world demonstration.
-
Protocol
-
Integrating-sphere calibration; tests under incandescent, LED, fluorescent and daylight sources; illuminance/CCT and angular-response characterization; near-corneal melanopic irradiance compared with a portable spectroradiometer.
-
Reported findings
-
The development study reports satisfactory agreement with commercial reference equipment and demonstrates coordinated near-corneal light recording during a field experiment.
-
Limits of interpretation
-
Developer-led characterization and a limited demonstration; the reported results do not establish performance under every spectrum, wearing position or field condition.
-
Source inspected
-
Full text
-
Evidence location
-
Sections 2.5 and 3.1; Figures 8–9 (illuminance/CCT/angular tests); Section 3.3 and Figures 10–11 (melanopic irradiance comparison).
-
Curation note
-
Published online 13 February 2023. The article describes lido and its calibration workflow. Its field demonstration concerns melanopic irradiance, which should not be relabeled melanopic EDI.
DOI: 10.1177/14771535221147140
PubMed record ↗
Dhakal et al. · 2022 · Peer reviewed
-
Journal / server
-
Ophthalmic and Physiological Optics
-
Devices
-
MyLyt
-
Measurements
-
Illuminance
-
Device-specific coverage
-
MyLyt: Illuminance
-
Setting
-
Laboratory + field
-
Evidence type
-
Reference comparison
-
Reference
-
Factory-calibrated Sinometer LX1330B lux meter; activity diaries for indoor/outdoor classification.
-
Protocol
-
Four trackers were tested in a controlled chamber and indoor/outdoor settings. A field phase included 21 adults and eight children.
-
Reported findings
-
Repeated and between-unit measurements were consistent. Reference agreement varied by setting; diary-based indoor/outdoor classification had high sensitivity and specificity in this sample.
-
Limits of interpretation
-
Classification uses self-reported location. Illuminance agreement is not proof of accuracy for spectra or melanopic quantities.
-
Source inspected
-
Full text
-
Evidence location
-
Methods: Phase 1/2 validation; Results: Figures 3–5 and Tables 2–4.
-
Curation note
-
Online publication 22 October 2022; issue year 2023.
DOI: 10.1111/opo.13061
PubMed record ↗
Bhandari, Mirhajianmoghadam & Ostrin · 2021 · Peer reviewed
-
Journal / server
-
Sensors
-
Devices
-
Clouclip (version not reported); Actiwatch Spectrum Plus
-
Measurements
-
Illuminance
-
Device-specific coverage
-
Clouclip (version not reported): Illuminance | Actiwatch Spectrum Plus: Illuminance
-
Setting
-
Field
-
Evidence type
-
Wearable-to-wearable comparison
-
Reference
-
Concurrent spectacle-mounted Clouclip, wrist Actiwatch Spectrum Plus, daily logs and questionnaire.
-
Protocol
-
Twenty-five adults wore both devices for one week. Illuminance and time above the outdoor threshold were compared with each other and self-reports.
-
Reported findings
-
Wrist Actiwatch illuminance was systematically lower than Clouclip. Questionnaire estimates of outdoor time exceeded both device estimates.
-
Limits of interpretation
-
Placement and device are confounded. This study evaluates agreement and behaviour estimates, not absolute sensor accuracy against a photometer.
-
Source inspected
-
Full text
-
Evidence location
-
Sections 2.2–2.3 and light-exposure results.
DOI: 10.3390/s21217096
PubMed record ↗
Falck et al. · 2021 · Peer reviewed
-
Journal / server
-
Journal of Alzheimer's Disease Reports
-
Devices
-
MotionWatch 8
-
Measurements
-
Illuminance
-
Device-specific coverage
-
MotionWatch 8: Illuminance
-
Setting
-
Laboratory + field
-
Evidence type
-
Reference comparison
-
Reference
-
Extech LT40 LED light meter.
-
Protocol
-
Seventeen everyday scenarios were sampled for five minutes each, including tests with and without sleeves. Thresholds classified light/dark, electrical/daylight and bright-light therapy.
-
Reported findings
-
The watch distinguished some lighting classes but had poor absolute agreement and did not reliably identify bright-light therapy. Sleeves commonly reduced readings.
-
Limits of interpretation
-
Scenario-specific thresholds are not universal. A small controlled wear demonstration cannot establish general free-living accuracy.
-
Source inspected
-
Full text
-
Evidence location
-
Methods; Table 3; Figures 1–4.
DOI: 10.3233/ADR-200242
PubMed record ↗
Howell et al. · 2021 · Peer reviewed
-
Journal / server
-
Ophthalmic and Physiological Optics
-
Devices
-
Actiwatch 2; Clouclip (second generation)
-
Measurements
-
Illuminance
-
Device-specific coverage
-
Actiwatch 2: Illuminance | Clouclip (second generation): Illuminance
-
Setting
-
Field
-
Evidence type
-
Reference comparison
-
Reference
-
Manufacturer-calibrated Hagner S2 universal photometer.
-
Protocol
-
Devices on a skeleton were compared with a photometer at matched sensor positions in nine indoor/outdoor settings. Five Clouclip M2 units were also compared concurrently.
-
Reported findings
-
Both devices underestimated illuminance despite high correlations. Clouclip more closely reproduced the reference in the tested range; its between-unit illuminance ICC was 0.85.
-
Limits of interpretation
-
Device-reference trials were separate and covered different ranges. Indoor locations can exceed 1,000 lx; an illuminance category is not necessarily an outdoor location.
-
Source inspected
-
Full text
-
Evidence location
-
Methods: Devices employed and Validity; Results: Tables 2–4, Figures 3–5.
DOI: 10.1111/opo.12860
PubMed record ↗
Mohamed et al. · 2021 · Peer reviewed
-
Journal / server
-
Optics Express
-
Devices
-
Mohamed et al. spectrophotometer
-
Measurements
-
Angular response; Illuminance; Melanopic EDI
-
Device-specific coverage
-
Mohamed et al. spectrophotometer: Illuminance, Melanopic EDI, Angular response
-
Setting
-
Laboratory
-
Evidence type
-
Characterisation
-
Reference
-
Konica Minolta CL-500A calibrated illuminance spectrophotometer.
-
Protocol
-
A pendant/clip spectrophotometer covering 380–780 nm was developed and tested with common light sources; corrections addressed directionality, dark noise, saturation, nonlinearity, stray light and spectral response.
-
Reported findings
-
After correction, the reported α-opic EDI errors were below 7% for the four tested source types. Optical modification improved angular response; remaining spectral errors differed by source.
-
Limits of interpretation
-
Bench testing of a prototype with four source types does not establish accuracy for every spectrum or wearing condition. No equivalence to a later branded device is inferred.
-
Source inspected
-
Full text
-
Evidence location
-
Sections 2.2 and 3; Table 1 (angular response), Table 2 and Figure 8 (source comparisons).
DOI: 10.1364/OE.431373
PubMed record ↗
Full text ↗
Nagra et al. · 2021 · Peer reviewed
-
Journal / server
-
Journal of Medical Systems
-
Devices
-
Actiwatch Spectrum Pro
-
Measurements
-
Illuminance
-
Device-specific coverage
-
Actiwatch Spectrum Pro: Illuminance
-
Setting
-
Laboratory
-
Evidence type
-
Repeatability study
-
Reference
-
Controlled Gretag Macbeth Judge II lightbox; comparison among four watches and two sessions.
-
Protocol
-
RGB and white outputs were recorded under simulated daylight D65, illuminant A and cool-white fluorescent light.
-
Reported findings
-
Significant between-watch differences occurred under all three illuminants; repeated measurements also differed for most watch/channel combinations.
-
Limits of interpretation
-
Four units. This establishes variability, not traceable absolute illuminance accuracy. Despite the title, the tested watches are all Spectrum Pro.
-
Source inspected
-
Full text
-
Evidence location
-
Abstract; Methods: illumination conditions and procedure; Results.
DOI: 10.1007/s10916-020-01694-4
PubMed record ↗
Webler, Chinazzo & Andersen · 2021 · Peer reviewed
-
Journal / server
-
Journal of Physics: Conference Series
-
Devices
-
Spectrace
-
Measurements
-
Angular response; Illuminance
-
Device-specific coverage
-
Spectrace: Illuminance, Angular response
-
Setting
-
Laboratory
-
Evidence type
-
Characterisation
-
Reference
-
Reference spectra; LMT Pocket-Lux 2 for angular-response measurements.
-
Protocol
-
Prototype tests examined spectral reconstruction, angular response and intensity linearity; a separate survey assessed wearability.
-
Reported findings
-
Measured angular mismatch was 2.07%. Spectral reconstruction and intensity response depended on the tested signal and source conditions.
-
Limits of interpretation
-
Prototype and conference paper. Spectral recovery demonstrations do not establish arbitrary-spectrum reconstruction or a separately validated melanopic EDI output.
-
Source inspected
-
Full text
-
Evidence location
-
Sections 2.1 and 3.1.1–3.1.3; Figures 1–4.
-
Curation note
-
Full conference proceedings paper (CISBAT 2021), not an abstract.
DOI: 10.1088/1742-6596/2042/1/012120
Wen et al. · 2021 · Peer reviewed
-
Journal / server
-
Acta Ophthalmologica
-
Devices
-
Clouclip (first generation)
-
Measurements
-
Illuminance
-
Device-specific coverage
-
Clouclip (first generation): Illuminance
-
Setting
-
Laboratory + field
-
Evidence type
-
Reference comparison
-
Reference
-
Konica Minolta T-10 illuminance meter.
-
Protocol
-
Fifteen first-generation units were tested in 28 light environments spanning 50–38,000 lx, with repeated measurements. A separate participant study compared device records with questionnaires.
-
Reported findings
-
Controlled light tests reported a maximum relative error of 2.23% and high within- and between-unit consistency.
-
Limits of interpretation
-
Questionnaires are not a traceable illuminance reference. Results apply to the first-generation units and tested environments.
-
Source inspected
-
Full text
-
Evidence location
-
Methods: Validation of Clouclip; light-intensity validation results.
DOI: 10.1111/aos.14785
PubMed record ↗
Bhandari & Ostrin · 2020 · Peer reviewed
-
Journal / server
-
Ophthalmic and Physiological Optics
-
Devices
-
Clouclip (second generation)
-
Measurements
-
Illuminance
-
Device-specific coverage
-
Clouclip (second generation): Illuminance
-
Setting
-
Laboratory + field
-
Evidence type
-
Reference comparison
-
Reference
-
Dr. Meter LX1330B digital lux meter.
-
Protocol
-
Clouclip and reference sensors were aligned in indoor and outdoor locations, including shade and direct sunlight. The paper separately tested viewing distance.
-
Reported findings
-
Illuminance was strongly correlated with the reference, but disagreement grew at high levels, particularly above 20,000 lx.
-
Limits of interpretation
-
Distance performance does not establish light accuracy. Staged measurements do not reproduce continuous on-body occlusion.
-
Source inspected
-
Full text
-
Evidence location
-
Methods: Ambient illumination; Results: Figure 7.
DOI: 10.1111/opo.12735
PubMed record ↗
Joyce, Zele, Feigl & Adhikari · 2020 · Peer reviewed
-
Journal / server
-
Journal of Sleep Research
-
Devices
-
GENEActiv Original; Actiwatch 2
-
Measurements
-
Illuminance
-
Device-specific coverage
-
GENEActiv Original: Illuminance | Actiwatch 2: Illuminance
-
Setting
-
Laboratory + field
-
Evidence type
-
Reference comparison
-
Reference
-
Calibrated laboratory-standard photometer.
-
Protocol
-
Compared device illuminance with a photometer under white LED light and natural sunlight; also tested neutral-density filters to extend measurement range.
-
Reported findings
-
At about 20,000 lux LED light, GENEActiv and Actiwatch 2 recorded about 50% and 25% of reference illuminance, respectively. At about 30,000 lux sunlight, GENEActiv saturated and Actiwatch 2 recorded about 46%.
-
Limits of interpretation
-
Absolute readings required correction under tested conditions. Temporal tracking does not imply absolute accuracy; reported correction factors should not be assumed universal across spectra or device versions.
-
Source inspected
-
Abstract
-
Evidence location
-
Abstract: photometer comparison, LED/sunlight under-reading, saturation and neutral-density filters.
-
Curation note
-
Journal of Sleep Research 29(5), e12963. Online publication December 2019; journal issue October 2020. Primary publisher abstract also verified at https://doi.org/10.1111/jsr.12963 . Additional reported endpoints: Linearity, Dynamic range.
DOI: 10.1111/jsr.12963
PubMed record ↗
Stone, McGlashan, Facer-Childs, Cain & Phillips · 2020 · Peer reviewed
-
Journal / server
-
Clocks & Sleep
-
Devices
-
GENEActiv Original
-
Measurements
-
Illuminance
-
Device-specific coverage
-
GENEActiv Original: Illuminance
-
Setting
-
Laboratory + field
-
Evidence type
-
Characterisation
-
Reference
-
J17 Luma Color illuminance meter; MK350N spectrometer for spectral measurements.
-
Protocol
-
Ten units tested under fluorescent and LED illumination, darkness, overcast outdoor daylight, narrowband blue/green/red LEDs and an infrared camera illuminator.
-
Reported findings
-
Outputs tracked illuminance but generally underestimated it, particularly below 100 lux. Accuracy depended on spectrum: green light was under-reported, red light over-reported, and infrared affected the measurements.
-
Limits of interpretation
-
Low-light accuracy varied by source. Recording relative light patterns or distinguishing indoor/outdoor conditions does not establish accurate absolute exposure in dim environments.
-
Source inspected
-
Full text
-
Evidence location
-
§2.1–2.4: devices, stimuli and protocol; Table 2 and Results: intensity accuracy, spectral/infrared effects and inter-device reliability.
-
Curation note
-
Clocks & Sleep 2(2), 143–152. Inter-device reliability is reported separately from repeatability; findings apply to tested hardware/software. Additional reported endpoints: Low-light response, Inter-device reliability.
DOI: 10.3390/clockssleep2020012
PubMed record ↗
Argüelles-Prieto et al. · 2019 · Peer reviewed
-
Journal / server
-
Frontiers in Physiology
-
Devices
-
Kronowise
-
Measurements
-
Illuminance
-
Device-specific coverage
-
Kronowise: Illuminance
-
Setting
-
Laboratory
-
Evidence type
-
Calibration study
-
Reference
-
Ocean Optics spectroradiometer with CC-3 cosine corrector; CIE S 026 calculations from reference spectra.
-
Protocol
-
Commercial lamps and sunlight were compared with three-channel Kronowise readings; separate calibration relationships were developed for natural and two artificial-light classes.
-
Reported findings
-
Source-specific transformations improved correspondence with reference visible and circadian-light estimates relative to raw outputs.
-
Limits of interpretation
-
Results depend on the source classifier and fitted calibration. The paper’s circadian channel is not automatically interchangeable with every modern melanopic EDI implementation.
-
Source inspected
-
Full text
-
Evidence location
-
Methods: calibration; Results: light-source classification and calibrated visible/circadian measurements.
DOI: 10.3389/fphys.2019.00822
PubMed record ↗
Ostrin · 2017 · Peer reviewed
-
Journal / server
-
Optometry and Vision Science
-
Devices
-
Actiwatch Spectrum
-
Measurements
-
Illuminance
-
Device-specific coverage
-
Actiwatch Spectrum: Illuminance
-
Setting
-
Laboratory + field
-
Evidence type
-
Calibration study
-
Reference
-
Lux meter and UV sensor; models unresolved in the inspected abstract.
-
Protocol
-
The paper reports indoor/outdoor device calibration in addition to 14-day recordings in 55 adults and comparisons with activity questionnaires.
-
Reported findings
-
An original calibration component is reported alongside the exposure study; numerical sensor agreement has not been extracted from the accessible abstract.
-
Limits of interpretation
-
Abstract-level calibration record. The observational refractive-error comparisons do not themselves validate the sensor; quantitative accuracy requires full-text extraction.
-
Source inspected
-
Abstract
-
Evidence location
-
Publisher abstract, Methods: calibration against a lux meter and UV sensor.
DOI: 10.1097/OPX.0000000000001013
PubMed record ↗
Price, Lyachev & Khazova · 2017 · Peer reviewed
-
Journal / server
-
Journal of the Optical Society of America A
-
Devices
-
MotionWatch 8; ActTrust; GENEActiv Original; Actiwatch 2
-
Measurements
-
Angular response
-
Device-specific coverage
-
MotionWatch 8: Angular response | ActTrust: Angular response | GENEActiv Original: Angular response | Actiwatch 2: Angular response
-
Setting
-
Laboratory
-
Evidence type
-
Characterisation
-
Reference
-
Photopic and photoreceptor sensitivity functions, cosine response and reference values for dynamic characterization.
-
Protocol
-
New optical tests and existing evidence were combined. This record indexes four complete-protocol models with individually identifiable spectral and angular results: MotionWatch 8, ActTrust, GENEActiv Original and Actiwatch 2.
-
Reported findings
-
Optical characterization covers directional and spectral sensitivity, linearity, dynamic range and resolution, with a proposed assessment protocol. Results are model- and channel-specific.
-
Limits of interpretation
-
Only abstract and publisher tables were inspected. Other models discussed in the paper are omitted here to avoid counting reused evidence or assigning combined model results to individual variants.
-
Source inspected
-
Abstract
-
Evidence location
-
Table 1: complete-protocol models; Table 2: spectral mismatch; Table 3: cosine-response error; Table 4: dynamic performance.
-
Curation note
-
Abstract and Tables 1–4 inspected. Indexed coverage restricted to individually identifiable spectral and angular tests. Additional reported endpoints: Linearity, Dynamic range, Resolution.
DOI: 10.1364/JOSAA.34.000545
PubMed record ↗
Markvart et al. · 2015 · Peer reviewed
-
Journal / server
-
LEUKOS
-
Devices
-
Actiwatch Spectrum
-
Measurements
-
Illuminance
-
Device-specific coverage
-
Actiwatch Spectrum: Illuminance
-
Setting
-
Laboratory
-
Evidence type
-
Between-unit calibration
-
Reference
-
Side-by-side comparison among 48 Actiwatch Spectrum units.
-
Protocol
-
RGB and white outputs were compared under different light sources to develop a field-calibration procedure.
-
Reported findings
-
The study documents between-unit response variation and proposes corrections based on concurrent measurements.
-
Limits of interpretation
-
Agreement after field correction does not by itself establish traceable absolute accuracy. Detailed correction coefficients require the full paper.
-
Source inspected
-
Abstract
-
Evidence location
-
Author-deposited abstract: study aim, device model and protocol.
DOI: 10.1080/15502724.2015.1020948
Figueiro, Hamner, Bierman & Rea · 2013 · Peer reviewed
-
Journal / server
-
Lighting Research & Technology
-
Devices
-
Daysimeter-S; Daysimeter-D; Actiwatch Spectrum
-
Measurements
-
Angular response; Illuminance
-
Device-specific coverage
-
Daysimeter-S: Illuminance, Angular response | Daysimeter-D: Illuminance, Angular response | Actiwatch Spectrum: Illuminance, Angular response
-
Setting
-
Laboratory + field
-
Evidence type
-
Characterisation
-
Reference
-
Photopic V(λ), cosine response and calibrated near-eye Daysimeter measurements for placement comparisons.
-
Protocol
-
Optical characterization and field comparisons: 12 adults over 65 wore Daysimeters at four body locations and a wrist Actiwatch; five days analyzed.
-
Reported findings
-
Daysimeters performed better photometrically than Actiwatch Spectrum. Wrist measurements differed from near-cornea exposure.
-
Limits of interpretation
-
Neither device qualified as a laboratory-grade photometer. Field evidence is from older adults; circadian light and stimulus are model-specific quantities, not CIE melanopic EDI.
-
Source inspected
-
Full text
-
Evidence location
-
§2.2.1, Figures 3–5: optical performance; §3.2–3.3, Figure 6: Daysimeter placement; Figure 7: wrist comparison.
-
Curation note
-
Five of seven days analyzed. Placement comparisons used Daysimeters; Actiwatch remained at the wrist.
DOI: 10.1177/1477153512450453
PubMed record ↗
Price, Khazova & O’Hagan · 2012 · Peer reviewed
-
Journal / server
-
Lighting Research & Technology
-
Devices
-
Actiwatch Spectrum
-
Measurements
-
Angular response
-
Device-specific coverage
-
Actiwatch Spectrum: Angular response
-
Setting
-
Laboratory
-
Evidence type
-
Characterisation
-
Reference
-
Optical characterization; abstract does not identify all reference instruments.
-
Protocol
-
Sixteen Actiwatch Spectrum units were evaluated for spectral response, directional response and dynamic range.
-
Reported findings
-
The paper reports optical performance and proposes calibration, deployment and analysis techniques for circadian studies.
-
Limits of interpretation
-
Only the abstract was inspected for this record. It supports the scope of testing, but is insufficient for a quantitative accuracy judgment.
-
Source inspected
-
Abstract
-
Evidence location
-
Abstract: 16 units; spectral response, directional response and dynamic range.
-
Curation note
-
Metadata and abstract verified at the authors’ institution: https://researchportal.ukhsa.gov.uk/en/publications/performance-assessment-of-commercial-circadian-personal-exposure–2/ . Lighting Research & Technology 44(1), 17–26. Additional reported endpoints: Dynamic range.
DOI: 10.1177/1477153511433171
Bierman, Klein & Rea · 2005 · Peer reviewed
-
Journal / server
-
Measurement Science and Technology
-
Devices
-
Daysimeter (2005 prototype)
-
Measurements
-
Illuminance
-
Device-specific coverage
-
Daysimeter (2005 prototype): Illuminance
-
Setting
-
Laboratory
-
Evidence type
-
Characterisation
-
Reference
-
Photo Research LRS 450 Light Standard; spectral matching against the photopic response.
-
Protocol
-
Two prototypes were checked for spectral response. Linearity was tested against an integrating-sphere source with an approximately illuminant-A spectrum.
-
Reported findings
-
Photopic spectral-mismatch values were 3.8% and 5.4%. The tested response departed from linearity by a few percent across roughly 3.5 decades of irradiance.
-
Limits of interpretation
-
Partial full-text extraction from the indexed author PDF. The instrument’s higher advertised range was not tested. This record does not establish modern melanopic EDI accuracy.
-
Source inspected
-
Partial full text
-
Evidence location
-
Author PDF, Section 3.1.3: Radiation measurement verification; Figure 3.
-
Curation note
-
Primary passage accessible through indexed PDF text; direct download failed. Additional endpoints await complete full-text inspection.
DOI: 10.1088/0957-0233/16/11/023
