Automatic Colony Counter

With all solid-state circuitry, the Model 920A is suitable for colony counting in petri dishes up to 150 mm in diameter. A 30-watt circular fluorescent lamp provides non-glare illumination, with a reversible background of either black or white. With a pressure sensor system that provides uniform sensitivity over the entire working field, counting can be accomplished with the standard marking pen (any pen) or optional counting probe. Each time a count is registered on the LED display (0-9999), the beeper gives an audible signal to verify entry.