A Spectral Luxmeter Built for All
Most light meters are built for an undefined purpose. We designed it for many applications and in a way that the user can custimize it as he needs it (wichi displays and evaluations). The LIGHTmetric® ONE measures full spectral irradiance, illuminance, correlated color temperature (CCT), color rendering (CRI, TM-30-20), and photosynthetic photon flux density (PPFD) – all from one ISO/IEC 17025 traceable-calibrated device.
That combination makes it equally suited to a film set, an architectural lighting audit, a horticultural research bench, or a manufacturing quality-control.
What Sets LIGHTmetric® ONE Apart
True Spectral Measurement
Captures the actual spectral power distribution from 360 nm – 830 nm instead of reconstructing it from separate few color channels, so readings hold up under LED, daylight or mixed lighting.
Comprehensive Color Science
Beyond CCT and x,y or u'v' the device calculates CRI, TM-30-20, SSI and TLCI 2012, plus a built-in Lee filter calculation for color-shift correction on set.
PAR & PPFD for Plant Research
A dedicated PPFD display in µmol/m²/s, backed by extensive PAR evaluation functions, makes artificial plant lighting easy to verify against a target spec.
Human-Centric & WELL-Compliant
Direct display of melanopic equivalent daylight illuminance supports human-centric lighting evaluations as required by the WELL Building Standard, for which the device is a licensed product.
Remote App Control
The iOS/Android app puts full remote control and readouts in your pocket via Bluetooth, and measurement data can be forwarded straight from a shoot for post-production.
Rotatable Head & Tripod Mount
The sensor head rotates to angle toward the light source without repositioning the whole device, and a rear tripod thread enables hands-free, vibration-free readings.
On-Set Data & Flash Sync
Log data straight to an SD card, or use the dedicated flash-synchronization port to measure flash duration and intensity for consistent studio exposures.
Experts in Light Measurement Since 1985
Every unit ships with its own factory calibration certificate from Gigahertz Optik's DAkkS-accredited ISO/IEC 17025 laboratory; registering your device unlocks the digital certificate and PC software.
Built for the Field, Not Just the Lab
- Compact, pocketable housing at 136 mm × 74 mm × 32 mm – light enough to carry all day, sturdy enough for daily field use.
- Rechargeable lithium-ion battery good for at least 8 hours per charge (full usage), topped up via any standard 5 V USB source.
- Rotatable sensor head to angle the receptor toward the source without repositioning the whole device or tripod.
- Rear tripod thread for hands-free, vibration-free readings during longer measurement series.
- Bluetooth app control for iOS and Android puts every reading, export and setting change in your pocket.
- One sensor, many metrics: CCT, lux, full spectrum, CRI, PPFD, SSI, and Lee-filter color-shift calculation, all from a single scan.
Every LIGHTmetric® ONE is a handheld spectroradiometer, not a filtered photometer: it captures the actual spectral power distribution from 360 nm – 830 nm with a precision, f2-classified cosine-corrected detector. Based on that it derives illuminance, color temperature and color-rendering , etc.. Each unit leaves the factory with its own calibration certificate which confirms traceability. Calibrated in our highest class ISO/IEC 17025 calibration laboratory.
Technical Specifications
Optical & Spectral
Connectivity & Control
Power & Build
PAR & PPFD: Measuring Light the Way Plants Use It
Plants don't respond to brightness the way the human eye does. Photosynthetically Active Radiation (PAR) describes the waveband that drives photosynthesis, and researchers evaluate it as a photon count rather than a simple energy value, because it is the number of light quanta absorbed by chlorophyll – not the raw energy – that governs plant growth. This quantity, the Photosynthetic Photon Flux Density (PPFD), is expressed in µmol/m²/s.
The LIGHTmetric® ONE has a dedicated PPFD display that shows both the spectral irradiance curve and the resulting PPFD value in real time, using the same cosine-corrected 10 mm entrance optics that make its photometric and colorimetric measurements traceable. That makes it equally usable on a horticultural research bench, in a greenhouse, or wherever grow-light output needs to be verified against a specification – no separate quantum sensor required.
ISO/IEC 17025: What Traceable Calibration Actually Means
ISO/IEC 17025 is the international standard that defines the general requirements for the competence of calibration and testing laboratories. It replaced the earlier EN 45001 and ISO/IEC Guide 25 in 1999, and forms the basis on which accreditation bodies mutually recognize each other's calibration certificates worldwide. A measurement traceable to this standard means the result can be followed back, through an unbroken chain of comparisons, to a recognized national or international reference.
Every LIGHTmetric® ONE ships with a factory calibration certificate which is calibrated in our ISO/IEC 17025 calibration laboratory. The device itself reminds the user when the recommended recalibration is due. For quality control, compliance documentation, or any measurement that may need to hold up to audit, that traceability – not just an accurate reading – is what makes a result defensible, traceability is key.
Frequently Asked Questions
What can the LIGHTmetric® ONE measure?
It measures full spectral irradiance, illuminance (lux), correlated color temperature (CCT), CIE 1931/1976 color coordinates (x,y and u'v'), color rendering via CRI, TM-30-18, SSI and TLCI 2012, photosynthetic photon flux density (PPFD), and melanopic and circadian light metrics – all from a single measurement.
Is the LIGHTmetric® ONE suitable for measuring plant grow lights (PAR/PPFD)?
Yes. It includes a dedicated PPFD display showing the photosynthetic photon flux density in µmol/m²/s alongside the spectral irradiance curve, making it suitable for horticultural and plant-research applications.
Is the calibration traceable and accredited?
Every device ships with a factory calibration certificate which gives its traceability based on our ISO/IEC 17025 calibration laboratory.
Which apps and interfaces does it support?
The LIGHTmetric® ONE app is available for iOS and Android via Bluetooth. The device also connects over USB 2.0 for use with the S-LIGHTmetric desktop software (Windows), and can save data directly to a FAT32-formatted SD card.
How long does the battery last?
At least 8 hours of continuous operation on a single charge from its rechargeable lithium-ion battery, via a standard 5 V USB connection.
Can it be mounted on a tripod or synced with a camera flash?
Yes. It has a rear tripod thread for stable, hands-free measurement, plus a dedicated flash-synchronization port for measuring flash duration and intensity in studio photography.
Ready to See What Full Spectral Measurement Can Do?
Talk to us about your application – film, architecture, lighting design, horticulture or quality control.
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