MAX sensor is in use for a range of fermentations and cell types MAX sensor is used for both low and high cell densities with optical densities ranging from less than 1 to greater than 100 MAX instrumentation can be directly coupled to host instrumentation and computers for on line monitoring and control through both analog outputs (4-20mA and 0-5v) and serial port RS232 MAX instrument calculates specific growth rate on line from OD data for display and output to host instrumentation