P7 Lux with no optics/ref

[HumanLumen]

Has anyone taken a reading of Lux at 1m on axis for a P7 C bin? I drove mine from a adjustable current source at 1.4 amps and recorded 101 Lux at 1m on a Maplin Gold Lightmeter, which I adjust to 116 Lux (calibrated against an RS Light meter). The P7 was heatsinked and measurement taken on peak reading within a few seconds of switch on.
Any other data from anyone, as a repository of what a typical P7 should give?
Cheers HL

 

[yaesumofo]

IMHO it may be more accurate to take this measurement after the light is on for a while. The light's true output can't be measured within a few seconds of powering it up. the while system needs time to settle in. I have set up a P7 in a mag with d cells direct driving the emitter. I would run the light for somewhere between 3 to 5 minutes before measuring the output.
Do this several times on fresh cells and you will be able to get an average output for YOUR P7.
The initial output will be higher than the average and is not an accurate representation of what the emitter is really up to once up to temperature.
Just my opinion.
BTW when my meterman 631 shows up from where ever it is hiding I will measure my Mag mounted P7.

Yaesumofo

 

[HumanLumen]

Whilst I agree that it is best to get a temperature stabilised reading for your 'system' once completely assembled to show what it will do in the real world, I was looking to do a comparson with everyone elses P7 without the variable of temperature playing a major part i.e. I was hoping for a mearement at the die temperature near ambient so I could see if my P7 is binned correctly/underachieving. That's why I put my meter on peak so it can get the max reading before the die heats up signifcantly (note that I power up using a current adjustable regulated supply set to 1.4Amps, then move the light sensor into the light field to stop any false readings created by start up overshoot on the PSU. The readings with this procedure is repeated several times with the equipment switched off between readings to ensure consistancy, Note that the heatsink temperture rise is negligable in this case).
Any Lux figures you can give (with conditions, i.e aprox die temp calculated from heatsink temp and thermal resistance if the die temp is left to rise to a stable temp etc) would b much appreciated.
Cheers,
HL

 

[StefanFS]

Mag 1D on one D LiION cell, regulated by AMC7135 drivers at 2.9-3A, after 1 minute at one metre: 220 lux with the head taken off.
Mag 1D on one D LiION cell, regulated by AMC7135 drivers at 2.3-2.4A, after 1 minute at one metre: 195 lux with the head taken off.
DT 1300 light meter.
Stefan

 

[HumanLumen]

Thanks StephanFS. Looks like your readings are about 8% higher than mine once correcetd from the datasheet graph.Having said that, your readings were nearer temp stabilistion, so the difference would be even greater than 8%. Any furthere data anyone?

Cheers,
HL