Abstract: A post-processing system is provided for cleaning and/or curing a part produced by solid freeform fabrication (SFF). The post-processing systems include a housing, a part retaining device to retain the part within the housing, and an actinic radiation source to cure the part with actinic radiation. The systems also include a fluid circulation device adapted to expose the part to cleaning fluid and/or to allow the cleaning fluid to absorb actinic radiation to permit filtration of removed build material to allow extended use of the cleaning fluid. Certain systems include a first rotating portion that can rotate the retained part about a first axis, and further systems include a second rotating portion that can rotate the retained part about a second axis. The systems also include additional features to provide safe and efficient cleaning and/or curing of parts produced by SFF.

Abstract: A method and apparatus are provided for distinguishing synthetic diamonds from natural diamonds by detecting the effect the synthetic diamonds have on a magnetic field. A counter can be provided for measuring counting transitions of an oscillator having an inductor in a frequency determining circuit. The inductor has a port therein for admitting a sample diamond for testing. First, the oscillations are up counted over a precise time interval with no sample present, and then a sample diamond is placed into coupled proximity with the inductor to change the frequency of the circuit by an amount related to the quantity of ferromagnetic material in the sample diamond. Thereafter, a down count is performed for the oscillations with the sample diamond in place over a second time interval equal to the first interval. The difference in the up counts and the down counts is determined and displayed in a digital readout as a measure of the degree of likelihood of the sample being synthetic.

Abstract: A counter is provided for measuring counting transitions of an oscillator having an inductor in a frequency determining circuit. The inductor is at least in part air-cored and has a port therein for admitting a sample diamond for testing. First, the oscillations are up counted over a precise time interval with no sample present, and then a sample diamond is placed into the pont to change the frequency of the circuit by an amount related to the quantity of ferromagnetic material in the sample diamond. Thereafter, a down count is performed for the oscillations with the sample diamond in place over a second time interval equal to the first interval. The difference in the up counts and the down counts is determined and displayed in a digital readout as a measure of the degree of likelihood of the sample being synthetic.