The report outlines the results of four field tests of two candidate methods for source PM10 measurement. The first method involves a new sampling train design which incorporates emission gas recycle (EGR) to avoid the anisokinetic sampling bias inherent in size specific emissions measurement. The second technique, the simulated Method 5 (SIM-5) approach, uses existing sampling hardware with an altered traversing protocol to minimize this bias. The results of the test series suggest that both techniques are sufficiently advanced that they should be documented in more detail for potential use as sampling methods. Further, more extensive testing should be performed in order to define precision, reproducibility, and comparability of each technique as well as identify potential sources of interference or bias.