Hach 1950Plus, Инструкция по эксплуатации инструмента, Страница: 100 / 188

Page 100
Calibration Menu
UVTOCOperation.fm
Section 6
4. Press ENTER. This selects valves V1 and V2 and places the analyzer in
an offline status, drawing water from the zero inlet port. The display
changes, as shown in the following screen.
• 20 ppm is the current gas CO
2
ppm in the current calibration.
• 295s is the current seconds in the countdown (from the
pre zero period).
• Last 17 ppm is the prior calibration zero water gas CO
2
ppm.
5. After the pre zero period, the analyzer displays the CO
2
gas reading and
a message indicating whether or not the reading is stable. Press ENTER
to progress to the next screen.
The analyzer automatically detects the criteria for stability and displays
STAB, however, the user is responsible for determining that the zero is
sufficiently stable to proceed. A longer exposure to DI water creates a
better zero calibration. This is especially true when the analyzer has been
exposed to high concentrations of TOC immediately prior to gas
calibration.
6. When the ppm CO
2
or mg/L TOC reading becomes stable, press ENTER
to lock the signal into the analyzer and display a fixed screen detailing the
live ppm CO
2
reading and prior zero ppm CO
2
reading.
7. Press CTRL then ENTER to go back to the prior screen and allow
repeated update of the zero. A manual zero will automatically result in the
active calibration being a manual calibration.
6.10.4 Manual Span Calibration
Enter the Manual Span calibration menu by pressing UP from the Manual
zero menu.
1. Press ENTER to select Manual Span and proceed to the calibration
standard value screen.
2 0 p p m 295s
L a s t 1 7 p p m
2 0 p p m STAB
L a s t 1 7 p p m
L i v e 2 0 m g / l
Z e r o 2 0 m g / l
M a n u a l s p a n
M a n u a l s p a n
* 1 0 0 0 m g / l *