Circadian and spectral measurement
If you want to measure how light can affect circadian rhythms, alertness, and mood, it’s best to use a spectrometer. To get results that you can see right away (and show to other other people), you need a new kind of software that makes it simple and fast to do.
Melanopic lux made easy, and a lot more
With f.luxometer™, you can measure light spectra with a portable meter and see circadian quantities like melanopic lux and M/P ratio instantly. Save the raw data and analyze it however you like. Or, when you want to, share your results online, in just one click.
Using the f.luxometer™ software with x-rite’s hardware, there’s now a low-cost way to look at the spectrum a light makes.
A tablet PC measuring light with x-rite spectrometer and f.luxometer™ software
i1Studio from x-rite
We use reference-grade instruments sometimes (when the last percent matters). But when it’s time to put a meter in a carry-on bag, we prefer a smaller meter that’s rather accurate and inexpensive, too.
The meter we recommend is the i1Studio spectrometer from x-rite. This meter connects to your laptop via USB, and on its own, it’s great at calibrating your screen and measuring the reflectance of surfaces.
2. Purchase a f.luxometer license
The f.luxometer system allows you to measure light and output the raw spectral data. It automatically computes circadian metrics as you measure (like Melanopic lux and M/P ratio). If you want to, you can easily share measurements via our cloud service.
This version is priced at $99 a year, which includes updates and as much cloud storage as you need. It's intended for one person to use on a couple machines, or for one meter on a shared machine.
Features (and Metrics)
- Melanopic lux and melanopic equivalent radiance
- CCT (color temperature), lux, and cd/m²
- Transmission measurement (for measuring filters and eyewear)
- Lucas photoreceptor responses for circadian research (all major photoreceptor responses that affect the ipRGCs)
- Spectral irradiance measurement (for general lighting, in uW/cm²/nm)
- Spot radiance measurement (from a screen or 10 degree patch, in uW/²/sr/nm)
- Saving data to the f.luxometer cloud service, with more analysis there, including advanced color metrics
- Optional saving of geo-location (e.g., to identify multiple buildings)
- Saving measurements to disk as CSV
- Ability to share and download measurements
- Color-related metrics including CRI, 10-degree observer, and CIE PO06
- Blue Light Hazard (IEC62471)
- PAR and some wildlife responses
- Several additional proposed circadian metrics
- Ability to view time-series measurements
- Capture can be done without a connection, and uploaded later
- macOS 10.8+ or Windows 7+ (Windows 8 for geo-location)
- Internet connection to activate and setup
- English language only
- 5 lux to 50,000 lux (ambient light)
- 0.2 cd/m2 to 1200 cd/m²
- CCT within about 300K
- x, y repeatability: ±0.002
- Fast measurement, 1.5 seconds per sample
- f.luxometer works well with Windows tablets like the Microsoft Surface.
- Inexpensive Windows 10 tablets (<$200) are available and are excellent for mobile use or remote monitoring of a building.
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