Hach 1950Plus, Инструкция по эксплуатации инструмента, Страница: 56 / 188

Page 56
Start–up Instructions
UVTOCCommissioning.fm
Section 4
4. Review the Menu Structure, Setup Menu, and Service Menu. In any of the
menus, press the ENTER key to move one column to the right. Press
CTRL + ENTER (ESCAPE) to move one column to the left.
5. Enter the Program Mode by pressing the CTRL + DOWN key to access
the Setup and Service Menus. The Service Menu is initially displayed;
access the Setup Menu by pressing the UP Arrow key.
Note: The Status screen is a very useful screen when operating the analyzer. At any
time, four items of interest can be viewed:
• Current gaseous carbon dioxide concentration in detector (ppm).
• Calculated liquid TOC concentration (above ppm reading applied
to active calibration).
• Temperature of IR Detector flow cell.
• Rate of change of the current concentration. Positive or Negative rate
of change.
Exiting the Service Menu will always
leave the instrument in stopped
status and will require restarting.
6. Using the UP and DOWN buttons, proceed to the Start/Stop Analyzer
screen and stop the analyzer by pressing ENTER. The lamps will
extinguish and the pumps will stop.
7. The concentration of the carrier gas should descend to less than 20 ppm.
Check it as follows
a. Stop the analyzer by selecting Stop Analyzer in the Main Menu (or by
simply entering the SERVICE MENU).
b. The carrier gas will continue to sweep through the instrument.
Determine the concentration by accessing the Status screen (press
UP twice from Main Operating Screen. When the Status screen is
reached, press ENTER to lock it into place).
If the carrier gas concentration is greater than 20 ppm, the carrier gas is of
poor quality, a leak is present, or the IR bench is out of calibration.
If the gas concentration quickly descends to 0.0 ppm, the IR bench is out
of calibration.
If a leak is suspected:
• Check tightness of fittings, barb connections, etc.
• Verify an air/gas interface in the UV reactor manifold. This interface
often shifts up and down where the carrier gas encounters the
upflowing persulfate and resample solution.
• In the upper electronics enclosure, pinch the right tygon tube shut.
Confirm that bubbles in the GLS U-tube consistently travel from front
to back. If they do not, a leak is present or the condenser is cracked.
• In the upper electronics enclosure, pinch the left tygon tube shut
(outflow from detector). Bubbles should consistently travel from front
to back of the GLS. If they do not, a leak is present at the flow cell on
the IR bench.