A commercial bacterial colony counter for semi-automatic track counting

The information one must obtain from a solid state track detector depends on the specific application. The most common information need is the measurement of track density. The number of tracks per unit area is commonly used in neutron and alpha dosimetry, for example, to determine radiation dose. In recent years, a class of semi-automatic counting systems has become available for under $15,000. These systems, usually developed for bacterial colony counting, are capable of measuring track density. The basic instrument is designed to count relatively large objects with low magnification using an illuminated stage. However, track counting can be done with an accessory television camera coupled to an optical microscope. Tracks from electrochemical etching can be counted easily with objectives as low as 2X. (author)