Hitachi 911 (now the Roche Hitachi 911) is a computerized chemistry analyzer. It uses plasma, serum, urine, and CSF sample types to execute in qualitative and vitro quantitative determination on a broad range of analysts. A fully automated, discrete analyzer comprising two units: control unit and analytical unit. Control unit is composed of a keyboard, a monitor (CRT), and a printer. The analytical unit involves a photometric measuring system, an ISE System and a CPU.Roche Hitachi 911 is a complete system with probes, manuals and waste outlet. It is capable of performing both potentiometric and photometric assays. For photometric assays, it has a throughput capacity of 360 tests per hour. Its ISE module, with a throughput of 760 tests per hour, allows the automatic calibration of sodium, potassium and chloride levels.