Experiments were conducted to support development of an equation of state (EOS) of detonation products for the high explosive, hexanitroazobenzene (HNAB) using a small-scale version of the sandwich test. The sandwich test is the 2-dimensional analogue of the well-known axisymmetric cylinder test. The 2-dimensional sandwich test allows experiments to be conducted on thin layers of explosive produced by physical vapor deposition (PVD). PVD provides repeatable geometries and microstructures. HNAB films were deposited onto three different thicknesses of tantalum substrates and then assembled into a symmetrical slab configuration by joining two identical small-scale samples to form the microsandwich. Velocity of the tantalum liner expansion during detonation was measured using photonic Doppler velocimetry (PDV). The experimental data could support EOS development using a shock-physics code.