I found a great article on PAR vs Lux meters. I just bought a lux meter and i was searching the web for a conversion and i found there isn't really one but below is a equation with constants to give a ball park of what par you have. i thinking of buying a PAR meter if my new Lux meter doesnt work out
http://www.advancedaquarist.com/2008/2/review#h2Lux to PAR If you have a lux meter, it is possible to convert lux to PAR. Since spectral quality plays a part in these conversions, each light source (actinic lamp, 6,500K metal halide, etc.) will have a difference factor.
The equation is:
Lux ÷ Constant = µmol·m2·sec
Lux to PAR Conversion Factors Light Source Constant
Sunlight 54
Warm White Fluorescent 76
Cool White Fluorescent 74
URI (now UV) Actinic Fluorescent 18
URI (now UV) Daylight Fluorescent 54
Actinic/Daylight Combination 38
Philips 03 Actinic Fluorescent 40
Panasonic 6,700°K Power Compact 72
Panasonic 7,100°K / 6,700°K Combination 55
Osram Powerstar Metal Halide 57
Ushio 10,000°K Metal Halide 54
Coralife 10,000°K Metal Halide 30
Venture "Daylight" Metal Halide 46
Radium "Blue" Metal Halide 51
Fusion Sulfur Lamp 41
Westron Mercury Vapor Lamp 70
Iwasaki 6,500°K Metal Halide 57