FlickerSpec: LED Flicker Test

Your LEDs shouldn't be giving you headaches. FlickerSpec turns your phone into a flicker meter, measures them at 240 frames per second, and tells you against published standards whether the light is safe.

Built for clinical and biomedical engineers, lighting designers, facility managers, and anyone tracking down eye strain, headaches, or visual fatigue in a room full of LEDs.

WHAT YOU MEASURE

Quick Measurement (free, unlimited)

Point the phone at a light and read it live:

• Dominant flicker frequency in Hz

• Percent Flicker (modulation depth) and Flicker Index

• Signal-to-noise ratio and a confidence rating

• Live luminance waveform and FFT spectrum

• Achieved frame rate, so you know the capture is valid

IEC Certified Measurement (Pro)

A 3-minute tripod capture for compliance documentation:

• Short-Term Flicker Severity (PstLM) per IEC TR 61547-1:2015

• EU Ecodesign 2019/2020 PASS/FAIL, threshold PstLM ≤ 1.0

• 8x oversampled LM flickermeter running at 1920 Hz

• Validated against all five IEC Table A.1 reference vectors

THE VERDICT

FlickerSpec applies IEEE 1789-2015 Recommended Practice 1, the low-risk level: modulation must stay

under 0.025 x frequency below 90 Hz, and under 0.08 x frequency from 90 Hz to 1250 Hz, above which

flicker is unrestricted. You can also set a custom percent-flicker threshold if you work to a

stricter internal limit; the badge, the saved record, and the PDF all follow whichever you selected.

COMPLIANCE DOCUMENTATION

Save each measurement to a session with a location label, fixture photo, GPS coordinates, and notes.

Export a single-measurement PDF or a session summary with a measurement table and aggregate pass/fail

counts. Reports carry your company name and logo, the verdict with the standard and threshold that

produced it, real measurement uncertainty, the FFT spectrum, and your calibration certificate

reference. CSV export is included for external processing.

CALIBRATION IS FREE

Calibration is not a paid feature. Before measuring, point your phone at the free companion

calibration web app on any monitor or laptop. FlickerSpec captures the known-frequency signal,

verifies accuracy, and issues a timestamped certificate valid for 30 days recording the reference

and measured frequency, error margin, device model, and app version. Every user calibrates free,

then measures without limits.

WHAT IT CAN AND CANNOT SEE

A 240 fps camera has limits, and we state them:

• 50, 60, and 100 Hz — reliable frequency and depth

• 120 Hz — frequency reliable; depth depends on runtime phase coverage

• Above 120 Hz, including PWM dimmers and kHz drivers — outside camera bandwidth

Modulation depth also depends on framing: fill the region of interest with the light itself, or

treat the reading as a lower bound.

FREE VS PRO

Free, forever, no account:

• Unlimited Quick Measurements

• Every raw metric: frequency, Percent Flicker, Flicker Index, SNR, confidence

• Live waveform and FFT spectrum

• Calibration and certificate generation

Pro — $49.99 one-time, no subscription:

• IEEE 1789-2015 PASS/FAIL compliance verdict

• IEC Certified Measurement with PstLM and EU Ecodesign verdict

• Measurement logging with GPS, photos, and location labels

• Single-measurement and session-summary PDF reports

• CSV export

• Calibration certificate document display

• Report header customization with your company name and logo

TECHNICAL SPECIFICATIONS

• Capture: 240 fps constrained high-speed Camera2 session, gap-free luminance sampling

• Photometry: ITU-R BT.709 luminance, exposure and white balance locked during measurement

• Metrics: Percent Flicker, Flicker Index, dominant frequency, SNR, confidence, PstLM

• Standards: IEEE 1789-2015 Recommended Practice 1, IEC TR 61547-1:2015 Annex A,

IES TM-39-25, Commission Regulation (EU) 2019/2020

• Reports: PDF and CSV via the share sheet

• Storage: on-device only, no cloud, no account, no tracking

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