The Hitachi 911 is a fully automated, discrete, computerized chemistry analyzer that uses serum, urine, plasma and CSF sample types to perform in vitro quantitative and qualitative tests on a wide range of alalytes. In addition it is capable of performing potentiometric and photometric assays. The Hitachi 911 analyzer is composed of two units; the analytical unit and the control unit: The Analytical unit consists of an ISE System, a photometric measuring system, and a CPU. The Control unit consists of a monitor (CRT), a keyboard, and a printer. Features of the Hitachi 911 include; STAT results available quickly, ready to use 24 hours per day, 360 tests/hr throughput (photometric), 720 tests/hr throughput with ISE (Ka+, Na+, Cl-), 46 programmable tests, automatic calibration, and refrigerated storage for 64 reagent containers.