SPI Supplies Calibrated Soda Lime Glass Microspheres are available for calibrating SEM, TEM, LM, confocal, and SPM instruments. Uniform soda lime glass microspheres have fewer spherical imperfections and inclusions than other glass microspheres. They also have better mechanical and thermal stability. Very useful for instruments requiring a higher density and more contrast to incident radiation than that provided by the polymer microspheres. These microspheres have trace amounts of metallic elements and this makes them easily detectable by energy dispersive spectroscopy (EDS) methods and improves their contrast and reflectivity in optical, ultrasonic and electron beam detection methods. In addition to electron microscopy, these borosilicate glass spheres can also be used for applications in flow tracing, filter checking, and instrument calibration. All products have been calibrated against NIST traceable standards.