Dear Forum,
I am a new arduino enthusiast and still rather inexperienced. I am working for a British company which is designing and installing biogas systems in rural Tanzania - which is where I am based. I am in the process of conducting some technical analysis of biogas lamps which are used with the biogas system. I would like to devise a test to measure the lux levels of lamps such as this one:
I am planning on placing a number of light sensors spaced inside a black box and measure the lux levels in the vertical and horizontal plane. My problem is that I am not sure which would be the best sensors to use with my Arduino Duemilanove.
Could anyone advice me which sensors would be most appropriate for this? I will order them from the UK as someone will be coming out to Tanzania in a couple of weeks who can bring them.
Many thanks,
Oliver
TSL230R could be it - a lightintensity to frequency converter for $6 - Light Intensity to Frequency IC - SEN-08940 - SparkFun Electronics
datasheet: - http://www.sparkfun.com/datasheets/Sensors/TSL230R-LF-e3.pdf
Arduino Tutorial - Arduino and the Taos TSL230R Light Sensor: Getting Started | The Roaming Drone
Should get you started!
Succes, don't know if you can order easily in rural Tanzania ? However ordering might be the easy part 
That TSL230R chip has high sensitivity in the infra-red, which might not be what you want - there is a defined spectral sensitivity curve for lux/lumen scale which more closely matches the typical human eye subjective response.
However if comparing similar lamps the sensitivity curve might be irrelevant... But I fear gas lamps vary in both colour-temperature and luminous intensity?
It's worth noting that if you're in the US, radio shack is selling the parallax tsl230r for $2. Cheap to try and easy to use.
Thanks for the replies. I have found these http://uk.farnell.com/taos/tsl230rp-lf/photodiode-sensor-l-volts/dp/1182355?Ntt=TSL230R on farnell in the UK, they seem to be the same thing, right?
Like I said, I am still fairly new to the Arduino world but I think I'll order these and give them a try, I might be back for some more assistance setting them up if I get stuck with the tutorial.
Any other suggestions for sensors would still be welcome as I have a few more days to order.
Thanks,
Oliver
That looks like the right unit. Your biggest problem will be calibrating the measurements returned from the sensor into lux or similar. Getting RELATIVE measurements and point graphing it should be easy, though, and there are sketches out there that should make it easy to get started.
I don't always get notifications from the forum, so please PM me if you reply and I don't notice. I have a dozen of these sensors and might be able to assist.