In 1992, Bubble Technology Industries introduced the very first truly portable commercial gamma spectrometer, the MICROSPEC. The MICROSPEC provided not only unprecedented portable spectroscopy but also provided highly accurate dosimetric data based on unfolding of the gamma ray spectrum.

NaI-based detectors have always been the best choice for field instruments, combining high efficiency and simplicity with good resolution at a reasonable cost. However, NaI basic response is a poor match to tissue response and its sensitivity varies dramatically with energy. In the BTI MICROSPEC system, NaI response functions and efficiencies are stored in the on-board computer. The acquired spectrum is stripped and used to calculate dose equivalent using internationally accepted energy-dose conversion coefficients. The result is a NaI-based system that provides highly accurate, energy-independent, tissue equivalent dose.

Over the years, BTI has continually refined the advanced MICROSPEC spectroscopic survey systems and has developed a unique line of probes, all providing accurate dosimetric information as well as spectroscopic data.