The documentation for how we test our lights, generating the performance certification which accompanies every light we sell, can be found here.
We're a science and engineering driven company. This means, above all, quality data is critical. Part of this reveals itself in our light packages, every light comes with an individual signed card identifying the light's performance. How do we acquire these numbers though, and how reliable are they?
Light meters are common, and relatively inexpensive, however reliability and performance over a range of conditions varies. To this end, we run a dual meter setup. Our primary meter is an Extech LT40, which we prefer as it is reliable and provides more accurate measurements of LEDs specifically. Our secondary meter, an LX1330B, exists as a backup. This is not only as a check to assure ambient conditions aren't significantly skewing measurements, but also in case an aberration rears its ugly head.
When measuring Kcd, precise distances are as critical as instrumentation. Unless otherwise specified, for individual certification, lights are measured at 6 meters. Distances under 30 meters are taken via tape. Longer distances, greater than 30 meters, are measured with a Redfield 550. All throw-based lights are double checked at 100 meters minimum to assure we're not generating the short-range skew utilized by some other manufacturers to boost performance numbers.