A screening test was developed at Los Alamos National Laboratory [1] that can be used to decide if a newly synthesized/formulated explosive might warrant further development. The test consists of firing a rate-stick composed of 12.7 mm diameter by 12.7 mm high pellets of different densities ordered from lowest to highest, initiated by a detonator at the low-density end of the stick. This poly-rho test yields detonation velocities over a range of densities using only the small amount of the explosive typically generated by the synthetic organic chemist at an early stage of the scale-up process. The amount of material required is far less than that required for the typical rate-stick series. This paper presents results on poly-rho tests that were conducted on three explosives commonly used at Los Alamos National Laboratory, namely PBX 9501, PBX 9502 and PETN. The results are compared with empirical detonation-theory predictions and existing explosive experimental data, with good agreement in all cases.