specially prepared metal wheel that is forced down upon the plate with a hydraulic press. The metal plate is then struck with a pendulum to move it, squeezing the explosives between plate and wheel as the plate moves. Initiation is determined, and analyzed by the Bruceton analysis or Neyer d-optimal test, as above. BAM friction testing is similar, except that the sample is placed on a ceramic plate which is then moved side-to-side as a ceramic peg exerts force on the sample. Electrostatic discharge. Testing for ESD, or "spark" sensitivity of explosives is performed with a machine designed to discharge from a capacitor through a prepared sample. The Sandia National Labs design employs a dipping needle that punctures a sample cell and discharges the spark simultaneously. The amount of energy discharged into the cell becomes the variable in which Bruceton analysis or Neyer d-optimal test is performed to determine spark sensitivity. Thermal sensitivity. Determining the point at which a compound is capable of detonating under confinement with thermal stress is useful. A fixed quantity of material is placed in an aluminum blasting cap shell, and pressed into place with an aluminum plug. The sample is immersed in a hot metal bath, and the time-to-detonation is measured. If over 60 seconds, a fresh sample is run again at a higher temperature. In this manner, it is possible to determine the temperature at which an explosive will detonate on the small scale. Unlike the other tests above, this figure is misleading as explosives have more thermal issues on the large scale. Therefore, the thermal sensitivity figures established using this technique are higher than one would expect in the real world. Thermal safety testing may also be performed via differential scanning calorimetry, in which a small (sub-milligram) sample is placed in a sample cell, and the temperature is increased slowly. The calorimeter determines how much energy is required to increase the temperature of the sample. Using this device, characteristics such as the melting point, phase transitions and decomposition temperature of an explosive may be determined. Used together, these numbers may be used to determine the potential threats afforded by energetic materials when employed in the field. It cannot be stressed enough that these figures are relative; when we determine that impact sensitivity of an explosive is lower for that of a tested explosive than PETN, for example, the number produced in the impact