"DOCN601 Series Dissolved Oxygen analyzers\/controllers are a rugged and dependable industrial grade microprocessor-based instruments that is extremely easy to use.Its large, bright LED digital display is clearly visible even in direct sunlight. It’s speedy calibration and simple operator interface makes this analyzer\/controller a favorite with instrumentation departments in a wide variety of demanding industrial and municipal applications. Frequently used functions are accessed through an intuitive step-through menu which is printed directly on the front panel for ease of navigation. By pressing the MENU key the operator scrolls through the menu, illuminating an LED beside the selected item and displaying the stored value. Arrow keys are used to change the value. Seldom used or set-once adjustments, such as password activation are located on DIP switches on the back of the swing-out front panel."