ANSI FL 1 - Metric in Consumer Packaging Standards

摘要

Anyone who has purchased a flashlight in the US in the past few years will have noticed certain changes in this mundane product. For one thing, with the advent of white LEDs, even small flashlights put out a prodigious amount of light compared to their incandescent forebears. Manufacturers had a choice of either making flashlights that would shine a lot longer, or shine a lot brighter, and the trend has been to the latter. The other difference one notices is the common set of icons that almost all manufacturers have adopted: the ANSI FL 1 standard. The voluntary standard defines a set of conditions and measurements for flashlight products and how the results may be displayed on packaging. Numbers inside of well-defined icons are displayed, and show such parameters as total light output, beam intensity, working distance, shock resistance (how far it can be dropped on hard surface without significant damage), resistance to immersion in water, and so on. The good news is that all the units are metric. Sure, that result is helped along by there being no other units for light output (lumens) and beam intensity (candelas) other than metric ones, but the distances are expressed in meters. For example, the working distance is defined as the distance in meters at which the illuminance falls to 0.25 lux. The survivable drop height is expressed in meters. The water depth at which the device will not be damaged if immersed for a set time is shown in meters. I think the standard allows some values to be stated in feet, but the icons always display meters, allowing side by side comparison with other products.