how does light lumes get measured

[skullcandy]

i want to measure the lumes in my lights and dont know how, anyone one hear know how to explain that to me ?

 

[pcduck]

You would need to buy a light meter.

Bulbs when new come with an initial lumens but that decreases with age. That is why a light meter is necessary.

 

[BackWoodsDrifter]

Yup ifin yual look on the package when yual buys the light it says how many lumens it puts off, they done the measurin fur ya but like Duck said they weeken with age. Package says it all

BWD

 

[4u2sm0ke]

You would need to buy a light meter.

Bulbs when new come with an initial lumens but that decreases with age. That is why a light meter is necessary.

:yeahthat:

all though they are a bit spendy..I just replace my bulbs...


take care and be safe

 

[Hushpuppy]

Typically your lights are measured in lumens. That is a measure of the amount of light energy that the bulb is emitting. However, most light meters do not measure lumens. They measure either Lux or foot-candles. The reason for this is that the light core tube emits light energy in 360degrees around the light, while the meter is only recieving the energy that is shined directly on it from the bulb, and any that is reflected to it from the hood or walls. For this reason the lux or foot-candles will never match up to the lumens of the bulb. Also, the farther away the meter is the lower the Lux will be due to the dispersion of the photons of light. If you think of light shining on a surface like it is water spraying out evenly over the same area. The farther away the nozzle is from the surface the more spread out the spray will be and there will be more area of the surface that will not get wet initially due the the water droplets spreading out in the spray from the source.

The only accurate way to test your bulbs with a meter to see if they are weakeningis to test a new bulb of the same wattage in the same ballast first to get a "new baseline" reading (and do it at a set and measured distance), then replace the new bulb with the older bulb and test at the same measured distance. This will give you the most precise reading of where you older bulb is. But you can measure multiple bulbs (if you have multiple lights) and see if there are any that are way weaker than the others. This is not as precise a measurement but will suffice if you think you have a weak bulb. Just remember to measure directly below the light and at the same distance for all lights measured.