About the lux measurement...help, please...

[msxtr]

Hi, I have bought this "multimeter" in the Lidl, this put that have luxmeter in 2 scales 1 to 4000 and 4000 to 40000 lux, well, if I use my light with her, this exceed the scale of 40000 lux, is this posible?? I don't understand nothing....help, please....

Gruss - Saludos

José

 

[etiam]

just keep more distance between the light and the measurement instrument. double the distance and your intensity will be just a 1/4.. triple the distance intensity will be a 1/9. intensity will fall with the power of two.
after that you can compare your lights. note that the lightmeter is calibrated on 2850K white light. colourchanges will have influence in your measurements.

greez

 

[mwulf]

At which distance did you measure?
If you hold it directly in front of the lamp you geht a high result.

For Example a Marwi Nightpro Extreme 10 W HID:

65 Lux * 10 m^2 = 6500 candela
6500 Lux in 1 m^2 =6500 candela
650.000 Lux in 0,1 m^2 =6500 candela

Ok, the 0,1 Meter I calculated theoretical, in reality it would be a difference because this lamp isn't a point source ...

The normal measuring Distance for lamps in Germany is 10 meter because this is defined in the StVZO ... if you want to measure the brightness of sunlight you won't get a differenze if you hold it one meter higher because the distance form the sun to the earth is nearly the same as this distance minus 1 meter.

 

[msxtr]

Hi, thanks to both for your help!!!!

etiam Yes, I would see that the calibration was to 2850K white light, so much affect this to the measurement??

mwulf I test the lights to 1 meter and 10 meters to see what happen...

Thanks again

Gruss - Saludos

José