Hach 51 Series User Manual page 13

Sensor installation
Sensor positioning
The sensor must be installed in a socket or flow chamber that allows contact with the sample fluid to
be analyzed. The sensor and measuring instrument are connected by a cable. The standard sensor
cable lengths are 3, 5, 10, 15 and 20 meters. Ensure that the sensor will be mounted:
• perpendicular to the pipe
• on a horizontal pipe section (or on flow-ascending vertical pipe)
• minimum of 15 meters away from the pump's discharge side
• in a place where the sample flow is stable and rapid, and as far as possible from:
• valves
• pipe bends
• the suction side of any pumps
• a CO injection system or similar
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Note: There may be situations where not all the above conditions can be met. If this is the case, or you have any
concerns, please consult your Hach representative to appraise the situation and define the best applicable solution.
User interface
Instrument controls
The instrument front panel provides:
• A touch screen acting as display, touch pad and keyboard.
• A LED, showing when the instrument is on.
Turning instrument On and Off
There is no power switch on the instrument. The mains must be disconnected to turn the instrument
off.
Measurement window
The main (numeric) measurement window continuously displays:
• Sensor measured values
• Measured sensor trends (for the last 10 minute to last hour)
• Measured sensor data alarm limits and other events
• Temperature
Touch screen
The user interface on the front panel is a touch screen providing easy selection through menus. All
the measurement, configuration, calibration and standard service routines can be called by pressing
buttons and menu bars on screen.
The display can be configured to only show a sensor measurement, or to show a parameterized
graphic representation of the last measurements.
English 13