wbp
Enlightened
- Joined
- Feb 11, 2008
- Messages
- 251
Re: Actual Lumens readings in 6" dia. Lab Sphere IS with SC 5500 control - PART II
No two spheres are going to be *exactly* the same; even a pro IS is sold with calibration or some provision for calibrating it in the field. Ask Gman how often his company's IS goes back for re-cal.
To measure lumens you don't need to adjust the meter. All you need is the correction factor for your meter and sphere system to put in your spread sheet.
Even with the same brand and model of light there is still variation in output due to the LED variation. If you want to measure lux accurately you have to have the meter calibrated. I can do this but it takes time and expertise I have had to develop, and often components have to be changed as well.
Don't forget - I've got $$$$$ invested in test equipment that allows me to do this. I want to help you guys out as much as I can, but I can't afford to give it away either. I would like to (need to) recover some of my costs... I think if enough people are interested in doing this then we can come up with something that is both reasonably accurate and reasonably affordable.
If I used the exact sphere as you and picked up a light that is consistent and used the same meter. Couldn't I put the light and meter in the box then read the number then ask you what the "right" reading should be (since you calibrated it). Then I assume in the back of the meter, I could adjust it?
Sorry if I misunderstood.
No two spheres are going to be *exactly* the same; even a pro IS is sold with calibration or some provision for calibrating it in the field. Ask Gman how often his company's IS goes back for re-cal.
To measure lumens you don't need to adjust the meter. All you need is the correction factor for your meter and sphere system to put in your spread sheet.
Even with the same brand and model of light there is still variation in output due to the LED variation. If you want to measure lux accurately you have to have the meter calibrated. I can do this but it takes time and expertise I have had to develop, and often components have to be changed as well.
Don't forget - I've got $$$$$ invested in test equipment that allows me to do this. I want to help you guys out as much as I can, but I can't afford to give it away either. I would like to (need to) recover some of my costs... I think if enough people are interested in doing this then we can come up with something that is both reasonably accurate and reasonably affordable.