Lighting Passport, created by three-year-old Taiwanese firm Asensetek, is a separate piece of hardware, with its own sensor and patented spectral engine, that clips on to the end of an Apple or Android phone (or you can carry it around separately, as long as the battery lasts and you keep your phone within Bluetooth range). Download the free app, and you’re good to go.
The device can measure all the key things – colour temperature, colour rendering (for colours R1-R15), light output, peak intensity, and illuminance. There are settings for measuring single or multiple light sources, or for continuous measurements over a period of time.
You can assess uniformity, compare spectral composition to a reference source, and export or email data to share the results. Your colleagues can download the free app so they can examine the numbers too – even if they don’t have a Lighting Passport themselves. You can compare colour data to either the International Electrotechnical Commission’s MacAdam ellipses or, for the US market, the standard Energy Star binning chart.
And to keep track of what you measured, you can save a photo of each light source you measure.