Abe, Dan,
We noticed a mistake in the calibration step in the scatter measurement.
We assumed that the camera was receiving all of the light emitted from the integrating sphere, when in fact it was receiving only 0.43%.
This reduces the result for all scattered light to 0.43%.
In other words, the 7/22 result is 4~7%*4.3*10^(-3)= 1.7~3.0*10^(-2)% ,instead of 4~7%.
(The reason for the wide range of values is that the intensity of the scattered light has an angular dependence.)
This means that the scattered light is about 170~300ppm.