The datasheets and catalog pages for commercial electroluminescent (EL) wire in hobby quantities, e.g., adafruit's, list brightness in candelas per square meter. That's ok for two-dimensional EL sheet, but not for one-dimensional wire.
(I understand that frequency and voltage affect brightness, as well as half-life, power consumption, color, etc.)
How do figures like 46 cd/m\$^2\$ convert to cd/m, which can be meaningfully compared to LED strips or neon tubes? Just consider the circumference of the cladding? Or of the phosphor? If there's multiple layers of phosphor, which one?
Also, the candela measures luminosity only in a particular direction, while EL wire has nontrivial off-axis brightness. Are there specs for lumens per meter of such wire?
Best Answer
Wire does not produce light one-dimensionally - it produces light in all directions and the intensity of the light is maximum right at the surface of the wire.
Imagine the light is emitted in all directions along the length of the wire - there is real power entering into the space between the wire and your eyes and, at any particular distance from the wire, the sum total of that power remains the same (just like it is on a radio antenna).
What happens at a greater distance is that the power per sq metre reduces because the surface area that the power is passing through gets bigger proportional to distance squared.
This is why the lumen per metre does not really mean anything. It's lumens per sq metre.