Here's a thread on the tar/soot soluble separation method for tar testing.

http://www.gekgasifier.com/forums/showthread.php?t=153 

Here's the quick "Q-tip" test

http://www.gekgasifier.com/forums/showthread.php?t=140

We need to elaborate this into formal instructions here.

Sampling and Analysis of Tar and Particles in Biomass Producer Gasses.  CEN Technical Report

http://gekgasifier.pbworks.com/f/TarSamplingandAnalysis.pdf