Microscope slide with 200 particles of various shapes and sizes. The SG7 was originally designed as a training tool, before more sophisticated particle analysis software systems became available. Operators were trained to estimate the size of a particle on the slide using a basic optical microscope and in doing so developed a uniformity in a group’s ability to characterize a powder sample.
With the advancement of computer recognition software, the need to produce an artifact that is capable of testing and calibrating a field of irregular particles addresses a real world issue. Each of the 200 shapes is numbered so that comparison can be done with particles in the specimen. It is also a useful tool for calibration and operator training. Typically these may comprise regular shaped features of different sizes so that the imaging software has known reference sizes to set its calibration. Alternatively, they may have a field area populated with 'random' shaped and sized features.
The SG7 is available as the test slide without particle characterization and one that includes a test report which accompanies the slide and includes information about each particle. For each particle a range of parameters are given and are listed in table form, ranked by the ID of the particle as seen on the reference slide.
The SG7 is not traceable to any international standard.